From dcohen at bgu.ac.il Fri Jan 2 18:19:02 2009 From: dcohen at bgu.ac.il (Doron Cohen) Date: Tue Feb 17 13:18:31 2009 Subject: [Phys-seminars] 2009-01-05 Condensed Matter Seminar / reminder Message-ID: <495E3E76.8030309@bgu.ac.il> *** THE SEMINAR WILL BE HELD AS PLANNED *** ----------------------------------------------------------- Condensed Matter Seminar DATE: 05-01-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Directed flow in nonadiabatic stochastic pumps SPEAKER: Saar Rahav, Department of Chemistry, University of California at Irvine ABSTRACT/COMMENTS: Molecular machines are molecules that perform specific tasks. They are ubiquitous in biological systems. Remarkably, it is now feasible to construct and manipulate artificial molecular machines. The operation of a stochastic pump, molecular machine driven by variation of its parameters, is analyzed theoretically. We derive a formula for the integrated flow from one configuration to another. We show that for adiabatic variation of the parameters this probability current is given by a geometric expression. We also find a surprising no pumping theorem for cyclic processes in thermally activated systems. From nano at bgu.ac.il Sun Jan 4 13:20:55 2009 From: nano at bgu.ac.il (Nano) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-07 cancellation-nanotechnolgy seminar Message-ID: This week's nanotechnology seminar is cancelled, due to the situation. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090104/4f902008/attachment.htm From physics at bgu.ac.il Mon Jan 5 12:59:12 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-07 Physical Chemistry Seminar Message-ID: <200901051059.MAA676239@tzin.bgu.ac.il> Physical Chemistry Seminar DATE: 07-01-2009 TIME: 16:00pm (Wed) PLACE: Bldg. 54, Room 207 (physics seminar room) TITLE: \"Simulation and control of quantum systems\" SPEAKER: Dr. Ilan Degani, Mathematics Department BGU ABSTRACT/COMMENTS: שימו לב - במידה והלימודים לא יחזרו התקיים כסדרם, בשל המצב הביטחוני נקיים את הסמינר במקום ממוגן - בכיתת המחשבים החדשה של המחלקה בבנין 29 קומה 1 חדר 102. במידה והלימודים יתקיימו כסדרם, הסמינר יתקיים במקומו הקבוע בחדר הסמינרים של המחלקה לפיזיקה From physics at bgu.ac.il Mon Jan 5 13:01:15 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-21 Astrophysics and Cosmology Seminar Message-ID: <200901051101.NAA675617@tzin.bgu.ac.il> Astrophysics and Cosmology Seminar DATE: 21-01-2009 TIME: 12:00 noon (Wed) PLACE: Physics building (#54) room 207 TITLE: The Galactic Center as a laboratory for gravitational wave source dynamics SPEAKER: Prof. Tal Alexander, Weizmann Institute ABSTRACT/COMMENTS: The massive Galactic black hole and the stars around it are a unique laboratory for studying how relaxation processes lead to close interactions of stars and compact remnants with the central massive black hole, in particular those leading to the emission of gravitational waves. I will review new results on the processes of loss-cone refilling by massive perturbers, resonant relaxation and mass segregation; describe observational evidence that these processes play a role in the Galactic Center; and discuss some of the cosmic implications. From mario at bgu.ac.il Mon Jan 5 13:08:04 2009 From: mario at bgu.ac.il (mario@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-08 Physics Colloquium Message-ID: <200901051108.NAA672617@tzin.bgu.ac.il> Physics Colloquium DATE: 08-01-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Can one count the shape of a drum? SPEAKER: Uzi Smilansky , Dept. of Complex Systems, Weizmann Institute of Science ABSTRACT/COMMENTS: Refreshments are served at 3:20pm From physics at bgu.ac.il Mon Jan 5 13:12:11 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-14 Astrophysics and Cosmology Seminar Message-ID: <200901051112.NAA671854@tzin.bgu.ac.il> Astrophysics and Cosmology Seminar DATE: 14-01-2009 TIME: 12:00 noon (Wed) PLACE: Physics building (#54) room 207 TITLE: Photon breeding mechanism and the emission of relativistic jets. SPEAKER: Prof. Juri Poutanen, Astronomy Division, Department of Physical Sciences University of Oulu, Finland ABSTRACT/COMMENTS: High-energy photons propagating in the magnetized medium with large velocity gradients can mediate energy and momentum exchange. Conversion of these photons into electron-positron pairs in the field of soft photons with the consequent isotropization and emission of new high-energy photons by Compton scattering can lead to the avalanche of the high-energy photons and pairs fed by the bulk energy of the flow. This is the essence of the photon breeding mechanism. We study the problem of high-energy emission of relativistic jets in blazars via photon breeding mechanism using 2D ballistic model for the jet with the detailed treatment of particle propagation and interactions. Our numerical simulations from the first principles demonstrate that a jet propagating in the soft radiation field of broad-emission line region can convert a significant fraction of its total power into radiation. The photon breeding mechanism produces a population of high-energy electrons (and positrons) and, therefore, alleviate the need for alternative (Fermi-type) particle acceleration mechanisms that have not yet been shown to produce high-energy leptons self-consistently. The mechanism reproduces basic spectral features observed in blazars including the blazar sequence (shift of spectral peaks towards lower energies at higher luminosities). The significant deceleration of the jet at sub parsec scales reconciles the discrepancy between the high Doppler factors determined by the fits to the spectra of TeV blazars and low apparent velocities observed at VLBI scales. The mechanism produces significantly broader angular distribution of radiation than that predicted by simple model assuming an isotropic emission in the jet frame. This helps to reconcile the observed statistics of FR I and BL Lac objects with the large Lorentz factors of the jets. From physics at bgu.ac.il Mon Jan 5 13:12:29 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-14 Astrophysics and Cosmology Seminar Message-ID: <200901051112.NAA673719@tzin.bgu.ac.il> Astrophysics and Cosmology Seminar DATE: 14-01-2009 TIME: 12:00 noon (Wed) PLACE: Physics building (#54) room 207 TITLE: Photon breeding mechanism and the emission of relativistic jets. SPEAKER: Prof. Juri Poutanen, Astronomy Division, Department of Physical Sciences University of Oulu, Finland ABSTRACT/COMMENTS: From physics at bgu.ac.il Mon Jan 5 13:22:33 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-08 Physics Colloquium Message-ID: <200901051122.NAA672450@tzin.bgu.ac.il> Physics Colloquium DATE: 08-01-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Can one count the shape of a drum? SPEAKER: Uzi Smilansky , Dept. of Complex Systems, Weizmann Institute of Science ABSTRACT/COMMENTS: Several decades ago M Kac asked his famous question : \"Can one hear the shape of the drum?\" - in other words- under which conditions, if at all, can the frequencies determine the shape of the drum\'s boundary. This problem has many important implications in physics and mathematics, and in the first part of the talk I shall review the present status of this subject. In the second part, I shall address the new version of the question, in which one replaces \"hear\" by \"count\". That is, instead of considering the sequence of frequencies, one considers the sequence of it nodal numbers of the corresponding wave functions. I\'ll show that this sequence of integers stores information on the shape of the drum. Moreover, counting the drum in this way can also resolve ambiguous drums which have different shapes but produce the same spectra of vibrations. From physics at bgu.ac.il Mon Jan 5 15:13:10 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-07 Physical Chemistry Seminar Message-ID: <200901051313.PAA682587@tzin.bgu.ac.il> Physical Chemistry Seminar DATE: 07-01-2009 TIME: 16:00pm (Wed) PLACE: Bldg 54, Room 207 TITLE: \"Simulation and control of quantum systems\" SPEAKER: Dr. Ilan Degani, Mathematics Department BGU ABSTRACT/COMMENTS: שימו לב - במידה והמצב הביטחוני יימשך, ולא תהיה חזרה ללימודים מיקום הסמינר יהיה במקום הממוגן כיתת המחשבים בנין 29 קומה 1 חדר 129 From physics at bgu.ac.il Mon Jan 5 15:19:28 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-07 Physical Chemistry Seminar Message-ID: <200901051319.PAA681648@tzin.bgu.ac.il> Physical Chemistry Seminar DATE: 07-01-2009 TIME: 16:00pm (Wed) PLACE: Bldg 54, Room 207 TITLE: \"Simulation and control of quantum systems\" SPEAKER: Dr. Ilan Degani, Mathematics Department BGU ABSTRACT/COMMENTS: Notice - If the Security situation will continue, the Seminar will take place in building 29 room 129. From AAHARONY at bgu.ac.il Tue Jan 6 11:15:19 2009 From: AAHARONY at bgu.ac.il (AAHARONY@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2008-01-19 Condensed Matter Seminar Message-ID: <200901060915.LAA754511@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 19-01-2008 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Non-linear magneto-resistance of two dimensional electron gas driven by the microwave radiation SPEAKER: Dr. Maxim Khodas, Brookhaven National Lab., NT, USA ABSTRACT/COMMENTS: NOTE: OUR CM SEMINARS CONTINUE AS USUAL, EVEN IF THERE IS NO FORMAL TEACHING. I start with the formulation of the problem motivated by the recent experiments in two dimensional electron systems in the presence of perpendicular magnetic field. The discussion is focused on an oscillatory magneto-resistance of the electron gas under the microwave or dc current excitations. The quasi-classical transport theory is demonstrated to successfully account for the current induced oscillations and microwave induced oscillations separately. I present the results of our analysis of the situation when both types of excitations are present. The resulting pattern of magneto-oscillations turns out to be described by rather simple expression in a remarkably good agreement with the existing experimental data. From ibar at bgu.ac.il Tue Jan 6 15:07:30 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-06 Lasers Seminar Message-ID: <20090106130738.9FC1F146CAC@smtp1.bgu.ac.il> Subject: ANNOUNCEMENT==> Lasers Seminar DATE: 06-01-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 The Lasers Seminar of today is canceled -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090106/f280e747/attachment.htm From avardi at bgu.ac.il Wed Jan 7 12:50:21 2009 From: avardi at bgu.ac.il (avardi@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-07 Physical Chemistry Seminar Message-ID: <200901071050.MAA844336@tzin.bgu.ac.il> Physical Chemistry Seminar DATE: 07-01-2009 TIME: 4:00pm (Wed) PLACE: Building #29, room 102 TITLE: Simulation and control of quantum systems SPEAKER: Dr. Ilan Degani , Mathematics Department, University of Bergen ABSTRACT/COMMENTS: We briefly overview some examples of quantum control problems appearing in different fields, ranging from existing technology (NMR/MRI) to research (control of nano devices, laser control of molecules). In all these examples the same type of problem emerges: to control a bilinear flow on a unitary (or orthogonal) group with piecewise constant controls. We review the existing optimal control approach, and point out some of its problems. Namely, the standard extremal control equations can not generally hold for piecewise constant controls; the only structural requirement from the controls is to have small $L_2$ norm. We then discuss our approach which derives the correct extremal equations, and which can prefer controls with desired structure. Particularly, we are able to compute optimal controls belonging to a desired subspace of control functions. Thus our methods may hopefuly be useful for computing controls which are producible by realistic laboratory lasers. Time permitting, we shall also discuss an efficient discretization scheme for Schrodinger equations based on Monge-Ampere PDEs. We compute coordinate transformations, from a computational domain to the physical one, which can zoom in or out of desired regions. In this way computational effort is concentrated where it is needed. Reference ----------- I. Degani, Monge-Ampere grids and the multidimensional mapped Fourier method, journal of chemical physics, 128 (2008) 164108. From mario at bgu.ac.il Wed Jan 7 19:55:41 2009 From: mario at bgu.ac.il (mario@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-08 Physics Colloquium ב י ט ו ל Message-ID: <200901071755.TAA871164@tzin.bgu.ac.il> Physics Colloquium ביטול DATE: 08-01-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Can one count the shape of a drum? SPEAKER: Uzi Smilansky , ABSTRACT/COMMENTS: הקולוקיום מבוטל From ibar at bgu.ac.il Thu Jan 8 12:19:25 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-13 Lasers Seminar Message-ID: <20090108101933.92FC4AB87E@smtp2.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 13-01-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Quantum Optics of Ultracold Neutral Atoms Using an AtomChip SPEAKER: Mr. Yenon Benhaim, Department of Physics, Ben Gurion University of the Negev ABSTRACT/COMMENTS: One-dimensional magnetic lattice traps for ultracold atoms can enable the study of quantum interference effects when matter waves from adjacent lattice sites overlap. I will describe how we prepare such matter waves using magnetic potentials generated by the micro-fabricated wires on the AtomChip. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090108/c48b5dcb/attachment.htm From mario at bgu.ac.il Sun Jan 11 14:06:41 2009 From: mario at bgu.ac.il (mario@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-15 Physics Colloquium Message-ID: <200901111206.OAA1173071@tzin.bgu.ac.il> Physics Colloquium DATE: 15-01-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: LHC and Physics Beyond the Standard Model SPEAKER: Prof. Ehud Duchovni, Dept. of Physics, Weizmann Institute of Science, ABSTRACT/COMMENTS: Refreshments are served at 3:20pm From physics at bgu.ac.il Sun Jan 11 14:48:07 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-14 Physical Chemistry Seminar Message-ID: <200901111248.OAA1178251@tzin.bgu.ac.il> Physical Chemistry Seminar DATE: 14-01-2009 TIME: 4:00pm (Wed) PLACE: * Bldg.54 Room 207(Physics Sminar room) TITLE: Linking Morphology and Performance of Polymer Solar Cells SPEAKER: Dr. Rafi Shikler , Department of Electrical and Computer Engineering BGU ABSTRACT/COMMENTS: Plastic electronic is a relatively new and rapidly growing field. Current products include devices such as polymer light emitting diodes, transistors, memories, smart cards and solar cells. Most of these products have comparable performance to solid-state devices. However, solar cells are still lagging far behind despite their economical potential. The study presented here is focused on understanding the role of polymer/polymer interfaces in organic solar cells and on new ways to improve their performance. I present a framework for the calculation of light absorption in multi-component polymer photocells. The model shows how carefully designed device structures can lead to a large enhancement in the light absorption by the device. I also present experimental results that show the effect of device morphology on its performance, in particular the effect of time evolution of composition next to polymer/polymer interface on device efficiency. * Notice - If the Security Situation will continue, the seminar will take plase in Bldg.29 Room 102. From physics at bgu.ac.il Sun Jan 11 15:19:32 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-12 Condensed Matter Seminar Message-ID: <200901111319.PAA1178455@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 12-01-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Many-electron theory of 1/f-noise and memory effects in hopping conductance SPEAKER: Professor Yiri Galperin, Department of Physics, University of Oslo, Oslo, Norway ABSTRACT/COMMENTS: We show that 1/f-noise of conductance in the variable range hopping regime is related to transitions of many-electrons clusters (fluctuators) between two almost degenerate states. Giant fluctuation times necessary for 1/f-noise are provided by slow rate of simultaneous tunneling of many localized electrons and by large activation barriers for their consecutive rearrangements. These fluctuations in the many-electron clusters are “read out” by the hopping cluster responsible for the conductance. We analyze statistics of the many-electron clusters responsible for noise at very low frequencies and calculate noise spectrum and intensity. In a broad temperature interval, the Hooge parameter steeply grows with decreasing temperature because it is easier to find a slow fluctuator at lower temperatures. Our conclusions agree with the low temperature observations of 1/f-noise in p-type silicon and GaAs. We also discuss relation of the 1/f noise and the observed memory effects in hopping conductance due to slow rearrangements of many-electron clusters leading to formation of polarons close to the electron hopping sites. An abrupt variation in the gate voltage changes occupation n umbers of the hopping sites, which then slowly relax due to rearrangements of the clusters. As a result, the density of hopping states becomes time dependent leading to the excess time-dependent conductivity. 1. A. L. Burin, B. I. Shklovskii, V. I. Kozub, Y. M. Galperin, and V. Vinokur, Phys. Rev. B 74, 075205 (2006). 2. A. Glatz, V. M. Vinokur, and Y. M. Galperin, Phys. Rev. Lett. 98, 196401 (2007). 3. A. L. Burin, V. I. Kozub, Y. M. Galperin, V. Vinokur, Phys. Rev. B 78, 132201, (2008); Journ. Phys-Cond. Mat. 20, 244135 (2008). From aaharony at bgu.ac.il Mon Jan 12 11:12:08 2009 From: aaharony at bgu.ac.il (Amnon Aharony) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-19 CM seminar Message-ID: Condensed Matter Seminar DATE: 19-01-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Non-linear magneto-resistance of two dimensional electron gas driven by the microwave radiation SPEAKER: Dr. Maxim Khodas, Brookhaven National Lab., NT, USA ABSTRACT/COMMENTS: NOTE: OUR CM SEMINARS CONTINUE AS USUAL, EVEN IF THERE IS NO FORMAL TEACHING. I start with the formulation of the problem motivated by the recent experiments in two dimensional electron systems in the presence of perpendicular magnetic field. The discussion is focused on an oscillatory magneto-resistance of the electron gas under the microwave or dc current excitations. The quasi-classical transport theory is demonstrated to successfully account for the current induced oscillations and microwave induced oscillations separately. I present the results of our analysis of the situation when both types of excitations are present. The resulting pattern of magneto-oscillations turns out to be described by rather simple expression in a remarkably good agreement with the existing experimental data. Professor Amnon Aharony, Department of Physics, Ben Gurion University, Beer Sheva 84105, Israel Tel. +972-8-6477558, Fax +972-8-6477008 Cell +972-54-4408558, E-mail aaharony@bgu.ac.il web: http://physweb.bgu.ac.il/~aaharony? -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090112/8745633d/attachment.htm From aaharony at bgu.ac.il Mon Jan 12 18:36:32 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-26 Condensed Matter Seminar Message-ID: <200901121636.SAA1271903@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 26-01-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: The noise spectrum of mesoscopic structures. SPEAKER: Eitan Rothstein, Physics Department, Ben Gurion Unibversity ABSTRACT/COMMENTS: Consider a mesoscopic system connected to two reservoirs. Mesoscopics objects are so small that fluctuations around the average properties become important. One way to characterize these fluctuations is to compute the current-current correlation function and its Fourier transform: the noise spectrum. In this talk I will start by reviewing some general features of the noise spectrum. Afterwards, I will give a short introduction to the scattering matrix formalism – a tool that enables us to calculate the noise spectrum analytically. I will also present the results of our calculations of the noise spectra for two mesoscopic structures: A single level quantum, and two such single level quantum dots connected in parallel. The noise spectra of these structures are calculated for a finite bias, a finite temperature, and with an Aharonov-Bohm flux. I will provide the physical interpretation for the interesting phenomena that appear in the noise spectra of these structures, such as: steps, peaks, and dips. From aaharony at bgu.ac.il Thu Jan 15 09:34:13 2009 From: aaharony at bgu.ac.il (Amnon Aharony) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-26 Condensed Matter Seminar Message-ID: ANNOUNCEMENT==> Condensed Matter Seminar DATE: 26-01-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Entropy in Crystal Nucleation of Hard Spheres SPEAKER: Dr. Eli Sloutskin, Harvard University ABSTRACT/COMMENTS: NOTE: THIS REPLACES AN EARLIER ANNOUNCEMENT FOR THIS DATE. Crystal nucleation is among the most important and fundamental processes in materials science. Yet this process is poorly understood, even in a system as simple as hard spheres. The most widespread paradigm that describes this process is "classical nucleation theory", an appealingly simple continuum approach that treats nuclei as spherical clusters of perfectly-ordered bulk crystals. Classical theory, however, fails by orders of magnitude to predict nucleation rates, which are difficult to measure; other predictions of the theory have never been carefully explored. This talk will present results of experimental studies of crystal nucleation in a suspension of hard sphere colloids. The experimental nuclei are not always spherical, as classical nucleation theory assumes, but instead adopt a far wider range of morphologies. These multiple conformations give rise to a configurational entropy, which we measure to quantify the free energy for actual nuclei formation. With this free energy, we obtain excellent quantitative agreement between experimental and theoretical morphology and size distributions, which highlights the importance of entropy in understanding crystal nucleation. Professor Amnon Aharony, Department of Physics, Ben Gurion University, Beer Sheva 84105, Israel Tel. +972-8-6477558, Fax +972-8-6477008 Cell +972-54-4408558, E-mail aaharony@bgu.ac.il web: http://physweb.bgu.ac.il/~aaharony? -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090115/d8ca654b/attachment.htm From ibar at bgu.ac.il Thu Jan 15 13:30:45 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-20 Lasers Seminar Message-ID: <20090115113101.6EFC5E3274@smtp2.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 20-01-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Optical parametric interactions for laser frequency conversion SPEAKER: Dr. Pinhas Blau, Electro-Optics Division, Soreq NRC, Yavne ABSTRACT/COMMENTS: Various "in band" applications, such as spectroscopy, remote sensing, and medical applications, require using specific wavelength laser light, while only limited parts of the spectrum are covered by existing laser sources. Optical parametric interaction in non-linear crystals enables converting the wavelengths of existing lasers from their original wavelength to shorter or longer wavelengths. Single, multiple or continuous tunable wavelength can be obtained. The basics of optical parametric interactions, as well as recent progress on optical parametric materials and configurations will be described. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090115/5ce3bcf3/attachment.htm From avardi at bgu.ac.il Thu Jan 15 14:02:31 2009 From: avardi at bgu.ac.il (avardi@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-21 Physical Chemistry Seminar Message-ID: <200901151202.OAA1518398@tzin.bgu.ac.il> Physical Chemistry Seminar DATE: 21-01-2009 TIME: 4:00pm (Wed) PLACE: Physics club (Building #54, room 207) TITLE: Optical and thermal effects in molecular conduction junctions SPEAKER: Prof. Avraham Nitzan, Department of Chemical Physics, School of Chemistry, Tel-Aviv University ABSTRACT/COMMENTS: From nano at bgu.ac.il Mon Jan 19 09:57:39 2009 From: nano at bgu.ac.il (Nano) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-21 Nanotechnology seminar Message-ID: <46E4339B3F2B4C5EAA3E05323F7BB7ED@estinano> Nanotechnology Seminar, Wednesday 21.1.09, 12:00 building 33, room 102 (still in a safe and authorized room) Chemical bath deposition of ZnO: The strong effects of impurities Gary Hodes, Department of Materials and Interfaces Weizmann Institute of Science Abstract: While TiO2 is the most commonly used oxide for nanoporous solar cells, there is considerable effort to use ZnO for this purpose. Among the potential benefits of ZnO are the ease of low temperature deposition as high surface area, single crystal nanocolumns or nanowires and the fast electron transport in these structures. Chemical bath deposition (CBD) is one of the more common methods of forming these nanostructures of ZnO. In almost all cases, a seed layer of ZnO is deposited by a different technique: CBD of ZnO in the absence of this seed layer is possible under certain closely-defined circumstances, but growth without this seed layer tends to be both irreproducible and results in poor quality films. We demonstrate how traces of impurities of certain transition metal compounds in the deposition solution can facilitate the deposition, resulting in adherent, reproducible films on any substrate in the absence of a seed layer. The impurities form nuclei on which ZnO can more easily grow. Based on the action of these nuclei, we can also, in some cases, treat the substrates by a simple solution dip to form nuclei on the substrate, thus allowing deposition to occur in the absence of the nuclei in the deposition solution. Finally, we show how these nuclei not only facilitate ZnO deposition, but how they can actually dictate the chemical nature of the deposit. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090119/5c3f073e/attachment.htm From physics at bgu.ac.il Mon Jan 19 10:39:00 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-21 Nanotechnology Workshop Message-ID: <200901190839.KAA1838069@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 21-01-2009 TIME: 12:00 (noon) PLACE: Chemistry club *(Building #33, room 102) TITLE: Chemical bath deposition of ZnO: The strong effects of impurities SPEAKER: Gary Hodes , Department of Materials and Interfaces Weizmann Institute of Science ABSTRACT/COMMENTS: *Notice - The change in room & building From physics at bgu.ac.il Mon Jan 19 11:34:53 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-22 Physics Colloquium Message-ID: <200901190934.LAA1831206@tzin.bgu.ac.il> Physics Colloquium DATE: 22-01-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Nonlinear Waves in Photonic Lattices: from Lattice Solitons and Photonic Quasi-Crystals to Anderson Localization of Light SPEAKER: Prof. Moti Segev, Dept. of Physics Technion ABSTRACT/COMMENTS: The recent progress on waves in nonlinear photonic lattices will be reviewed, with an emphasis on universal ideas that apply to all nonlinear periodic systems in which waves propagate. From nano at bgu.ac.il Wed Jan 21 10:45:34 2009 From: nano at bgu.ac.il (Nano) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-21 remainder nanotechnologies seminar is in the usual room Message-ID: <775FB14F614E4B6FB90360602BC01466@estinano> Nanotechnology Seminar, Wednesday 21.1.09, 12:00 building 29, room 306 Chemical bath deposition of ZnO: The strong effects of impurities Gary Hodes Department of Materials and Interfaces Weizmann Institute of Science Abstract: While TiO2 is the most commonly used oxide for nanoporous solar cells, there is considerable effort to use ZnO for this purpose. Among the potential benefits of ZnO are the ease of low temperature deposition as high surface area, single crystal nanocolumns or nanowires and the fast electron transport in these structures. Chemical bath deposition (CBD) is one of the more common methods of forming these nanostructures of ZnO. In almost all cases, a seed layer of ZnO is deposited by a different technique: CBD of ZnO in the absence of this seed layer is possible under certain closely-defined circumstances, but growth without this seed layer tends to be both irreproducible and results in poor quality films. We demonstrate how traces of impurities of certain transition metal compounds in the deposition solution can facilitate the deposition, resulting in adherent, reproducible films on any substrate in the absence of a seed layer. The impurities form nuclei on which ZnO can more easily grow. Based on the action of these nuclei, we can also, in some cases, treat the substrates by a simple solution dip to form nuclei on the substrate, thus allowing deposition to occur in the absence of the nuclei in the deposition solution. Finally, we show how these nuclei not only facilitate ZnO deposition, but how they can actually dictate the chemical nature of the deposit. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090121/2c8e0574/attachment.htm From ibar at bgu.ac.il Thu Jan 22 08:34:51 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-27 Lasers Seminar Message-ID: <20090122063506.457D2146BBE@smtp2.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 27-01-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Wafer inspection principles overview: Aspects of detection, system design, critical optical and electro-optical parameters SPEAKER: Dr. Roman Naidis, Applied Materials, Rehovot ABSTRACT/COMMENTS: -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090122/e94ab9f8/attachment.htm From physics at bgu.ac.il Thu Jan 22 15:28:40 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-28 Physical Chemistry Seminar Message-ID: <200901221328.PAA2119338@tzin.bgu.ac.il> Physical Chemistry Seminar DATE: 28-01-2009 TIME: 4:00pm (Wed) PLACE: Chemistry club (Building #29, room 306) TITLE: Solar-Driven CO2 Reduction Using Conjugated Photo-Thermal-Electro-Chemical (PTEC) Process SPEAKER: Dr. Gidon Fridman, Department of Environmental & Energy research, Weizmann Institute of Sciences ABSTRACT/COMMENTS: One of the most important and challenging problems facing humankind is the abundant, low-cost production of potent fuels, which can be used in intrinsically clean energy processes, that is, in processes whose net discharge has zero emission of green house gases and other pollutants. The general goal of the proposed study is to combine photo, thermal, electric and chemical (PTEC) processes to develop a new method that would maximize the efficiency and conversion rate of solar radiation to chemical potential in the form of CO2 reduction to CO and O2. The carbon monoxide can then be used directly as a gaseous fuel (e.g. in power or chemical plants) or converted to methanol or hydrocarbons. The CO2 generated during the burning of these fuels is trapped, returned to the solar power plant and reduced again. The proposed process uses concentrated solar radiation for reducing CO2 to CO in a series of coupled energy conversion steps, at temperatures of 800°C – 1400°C: Step 1. Concentrated sunlight heats the electron source – a Thermionic cathode combined with an electric field to enhance the electron emission – causing it to release electrons. Step 2. Electric field is generated from the heat supplied by the concentrated sunlight to provide the electrons with the right energy for dissociating CO2 molecules via dissociative attachment. Step 3. The electrons and preheated CO2 gas enter the main chamber where the Dissociative Electron Attachment (DEA) reaction (i) takes place, producing CO and negative oxygen ions. Step 4. Additional CO2 is dissociated by high-temperature electrolysis as it reaches an electrode which is in contact with an oxygen conducting membrane Step 5.The CO molecules exit the system, while the negative oxygen ions are drawn to the anode and reach it by traveling through a ceramic membrane. Upon reaching the anode the oxygen ions release their excess electrons, combine to form O2 molecules and exit the system, while the electrons are recycled back to the cathode. The present, ongoing project has two main objectives. The first is to derive the relations and calculate the theoretical and achievable efficiency of a system, which uses the PTEC process to produce CO. The second objective is to investigate experimentally a high efficiency electron source which uses the thermionic effect, operating in a CO2/CO/O2/O- gas surrounding. From gideonc at bgu.ac.il Sun Jan 25 11:48:38 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-29 Physics Colloquium Message-ID: <200901250948.LAA2346736@tzin.bgu.ac.il> Physics Colloquium DATE: 29-01-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Relativistic jets from astrophysical sources SPEAKER: Prof. Yuri Lyubarsky, Deptartment of Physics, BGU ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_A/Lyubarsky.html Refreshments are served at 3:20pm From physics at bgu.ac.il Sun Jan 25 14:57:32 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-02-05 Condensed Matter Seminar Message-ID: <200901251257.OAA2372427@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 05-02-2009 TIME: 11:00am (Thu) PLACE: Physics building (#54) room 207 TITLE: Pattern forming system in the presence of different symmetry-breaking mechanisms SPEAKER: Dr. Gabriel Seiden, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany ABSTRACT/COMMENTS: We report experiments on spatially forced inclined layer convection, where the combined effect of the intrinsic symmetry breaking due to a gravity-induced shear flow and spatially periodic 1D forcing is studied. We observed pattern selection processes resulting in stabilization of spatiotemporal chaos and the emergence of novel two-dimensional states. Phase diagrams depicting the different observed states for typical forcing scenarios are presented. Convection in the weakly nonlinear regime is compared with theory, and a good agreement is found. From nano at bgu.ac.il Mon Jan 26 10:35:57 2009 From: nano at bgu.ac.il (Nano) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-28 nanotechnology seminar Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/gif Size: 9132 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090126/149ce374/attachment.gif From AAHARONY at bgu.ac.il Mon Jan 26 11:04:14 2009 From: AAHARONY at bgu.ac.il (AAHARONY@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-02-02 Condensed Matter Seminar Message-ID: <200901260904.LAA2437112@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 02-02-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: The noise spectrum of mesoscopic structures SPEAKER: Eitan Rothstein, Physics Department, Ben Gurion Unibversity ABSTRACT/COMMENTS: THIS IS A NEW DATE FOR THIS SEMINAR. Consider a mesoscopic system connected to two reservoirs. Mesoscopics objects are so small that fluctuations around the average properties become important. One way to characterize these fluctuations is to compute the current-current correlation function and its Fourier transform: the noise spectrum. In this talk I will start by reviewing some general features of the noise spectrum. Afterwards, I will give a short introduction to the scattering matrix formalism – a tool that enables us to calculate the noise spectrum analytically. I will also present the results of our calculations of the noise spectra for two mesoscopic structures: A single level quantum, and two such single level quantum dots connected in parallel. The noise spectra of these structures are calculated for a finite bias, a finite temperature, and with an Aharonov-Bohm flux. I will provide the physical interpretation for the interesting phenomena that appear in the noise spectra of these structures, such as: steps, peaks, and dips. From aaharony at bgu.ac.il Mon Jan 26 11:08:23 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-02-09 Condensed Matter Seminar Message-ID: <200901260908.LAA2443658@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 09-02-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Active Transport on Disordered Microtubule Networks: The Generalized Random Velocity Model SPEAKER: Aviv Kahana, Department of Physics Ben Gurion University ABSTRACT/COMMENTS: The motion of small cargo particles on microtubules by means of motor proteins in disordered microtubule networks is investigated theoretically using both analytical tools and computer simulations. Different network topologies in two and three dimensions are considered, one of which has been recently studied experimentally by H. Salman et. al. (Biophys. J. {\\bf 89}, 2134 (2005)). A generalization of the random velocity model is used to derive the mean square displacement of the cargo particle. We find that all cases belong to the class of anomalous super-diffusion, that is sensitive mainly to the dimensionality of the network and only marginally to its topology. Yet, in three dimensions the motion is very close to simple diffusion, with sub-logarithmic corrections that depend on the network topology. When details of the thermal diffusion in the bulk solution are included, no significant change to the asymptotic time behavior is found. However, a small asymmetry in the mean microtubule polarity affects the corresponding long time behavior. We also study a 3-dimensional model of the microtubule network in living animal cells. Three first passage time problems of intracellular transport are simulated and analyzed for different motor processivities: (i) cargo that originates near the nucleus and has to reach the membrane, (ii) cargo that originates from the membrane and has to reach the nucleus, and (iii) cargo (e.g., mRNA) that leaves the nucleus and has to reach a specific target in the cytoplasm (e.g., the ribosome). We conclude that while a higher motor processivity increases the transport efficiency in cases (i) and (ii), in case (iii) it has the opposite effect. We conjecture that the balance between the different network tasks, as manifested in cases (i) and (ii) vs. case (iii), may be the reason for the evolutionary choice of a finite motor processivity. From physics at bgu.ac.il Mon Jan 26 11:33:25 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-28 Nanotechnology Workshop Message-ID: <200901260933.LAA2449019@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 28-01-2009 TIME: 12:00 (noon) PLACE: Chemistry club (Building #29, room 306) TITLE: Dye-Sensitized Solar Cells for Low Cost Multi-Bandgap Photovoltaics SPEAKER: Arie Zaban, Chemistry Department, Institute for Nanotechnology and Advanced Materials Bar-Ilan University ABSTRACT/COMMENTS: From ibar at bgu.ac.il Tue Jan 27 17:19:18 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-02-03 Lasers Seminar Message-ID: <20090127151911.828A2146CCF@smtp1.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 03-02-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Morphological Changes During the Cell Cycle of Escherichia Coli SPEAKER: Ms. Galina Reshes, Department of Physics, Ben Gurion University of the Negev ABSTRACT/COMMENTS: Bacteria are the simplest living organisms. In particular, the E. coli has been extensively studied and it has become one of the standard model systems in microbiology. However, optical microscopy studies of single E. coli have been limited by its small size, 1x3 ?m, not much larger than the optical resolution, ~ 0.25 ?m. As a result, not enough quantitative dynamical information on the life cycle of single E. coli is presently available. We suggest that, by careful analysis of images from phase contrast and fluorescence time-lapse microscopy, this limitation can be bypassed. For example, we show that applying this approach to monitoring morphogenesis in individual E. coli leads to a simple, quantitative description of this process. First, we find the time when the formation of the septum starts, ?c. It occurs much earlier than the time when the constriction can be directly observed by phase contrast. Second, we show that the E. coli grows in three linear regimes and that the corresponding growth rates are related to each other. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090127/5aa57a0d/attachment.htm From avardi at bgu.ac.il Wed Jan 28 01:19:37 2009 From: avardi at bgu.ac.il (avardi@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-02-04 Physical Chemistry Seminar Message-ID: <200901272319.BAA2593929@tzin.bgu.ac.il> Physical Chemistry Seminar DATE: 04-02-2009 TIME: 4:00pm (Wed) PLACE: Chemistry club (Building #29, room 306) TITLE: The ion-qubit tool-box SPEAKER: Dr. Roee Ozeri, We, Faculty of Physics, Weizmann Institute of Science ABSTRACT/COMMENTS: Current methods to implement a universal set of quantum gates on a register of laser cooled and trapped ion-qubits will be reviewed. Different ion-qubit choices and their respective gate implementation are described. The fidelity with which gates are implemented will be compared to that required to achieve Fault-tolerance. From avardi at bgu.ac.il Wed Jan 28 01:21:35 2009 From: avardi at bgu.ac.il (avardi@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-02-04 Physical Chemistry Seminar Message-ID: <200901272321.BAA2590356@tzin.bgu.ac.il> Physical Chemistry Seminar DATE: 04-02-2009 TIME: 4:00pm (Wed) PLACE: Chemistry club (Building #29, room 306) TITLE: The ion-qubit tool-box SPEAKER: Dr. Roee Ozeri, Faculty of Physics, Weizmann Institute of Science ABSTRACT/COMMENTS: Current methods to implement a universal set of quantum gates on a register of laser cooled and trapped ion-qubits will be reviewed. Different ion-qubit choices and their respective gate implementation are described. The fidelity with which gates are implemented will be compared to that required to achieve Fault-tolerance. From nano at bgu.ac.il Wed Jan 28 08:45:05 2009 From: nano at bgu.ac.il (Nano) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-01-29 Cancellation nanotechnology seminar Message-ID: <312169896B2B4653933B55F4950551C5@estinano> Due to personal reasons the nanotechnology seminar today has been cancelled. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090128/e82e2aa0/attachment.htm From nano at bgu.ac.il Thu Jan 29 11:32:01 2009 From: nano at bgu.ac.il (Nano) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-02-04 Nanotechnology seminar Message-ID: <39E543E230AF44019F271BAD21C76D9D@estinano> Nanotechnology Seminar, Wednesday 4.2.09, 12:00 building 29, room 306,Chemistry Department seminar room Calorimetric Studies of the Energetics of Nanomaterials and their Surfaces and Interfaces Alexandra Navrotsky Peter A. Rock Thermochmistry Laboratory and NEAT ORU University of California at Davis Abstract: Calorimetric studies of nanomaterials, using oxide melt solution calorimetry and water vapor adsorption calorimetry, have produced a wealth of data on the energetics of phase transformation and the surface energies of hydrated and dehydrated surfaces of nanoparticulate oxides. Competition between surface energy and phase transformation energy lead to crossovers in phase stability at the nanoscale. The surface energies of polymorphs metastable in the bulk are smaller than those of the stable polymorph and decrease with increasing metastability, regardless of the sign of the density difference. Wet surfaces have smaller surface enegies than dry ones. Oxyhydroxides have smaller surface energies than oxides. In ZnO, for which nanoparticles of different morphologies can be prepared, surface energy increases in the order nanoparticles, nanorods, nanoneedles, reflecting the predominance of different surface planes. Very recently, the interfacial energy of a dense nanoceramic sample of yttria stabilized zirconia (YSZ) has been measured. These results and systematic trends provide benchmarks for theoretical calculations. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090129/def54f23/attachment.htm From physics at bgu.ac.il Thu Jan 29 13:35:07 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-02-04 Nanotechnology Workshop Message-ID: <200901291135.NAA2722665@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 04-02-2009 TIME: 12:00 (noon) PLACE: Chemistry club (Building #29, room 306) TITLE: Calorimetric Studies of the Energetics of Nanomaterials and their Surfaces and Interfaces SPEAKER: Alexandra Navrotsky, Peter A. Rock Thermochmistry Laboratory and NEAT ORU University of California at Davis ABSTRACT/COMMENTS: From physics at bgu.ac.il Thu Jan 29 13:37:03 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-02-03 Nanotechnology Workshop Message-ID: <200901291137.NAA2723976@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 03-02-2009 TIME: 16:15(noon) PLACE: Chemistry club (Building #59, room 235) TITLE: Ligand-receptor binding in confined environments: from specific protein adsorption to nanoparticle attachment and drug delivery SPEAKER: Igal Szleifer, Dep. of Biomedical Engineering, Dep. of Chemistry and Dep. of Chemical and Biological Engineering Northwestern University ABSTRACT/COMMENTS: From gideonc at bgu.ac.il Sun Feb 1 11:36:11 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Tue Feb 17 13:18:32 2009 Subject: [Phys-seminars] 2009-02-05 Physics Colloquium Message-ID: <200902010936.LAA2970759@tzin.bgu.ac.il> Physics Colloquium DATE: 05-02-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Transport in Almost Perfectly Conducting Correlated Electron Systems SPEAKER: Prof. Efrat Shimshoni, Department of Mathematics-Physics, University of Haifa ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_A/Shimshoni.html Refreshments are served at 3:20pm From nano at bgu.ac.il Sun Feb 1 15:57:10 2009 From: nano at bgu.ac.il (Nano) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-04 Nanotechnology seminar, notice the change of speaker Message-ID: <6377BBB0D29F4EDB9C1DB9D45A75D69B@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/gif Size: 29385 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090201/4f2c2b48/attachment.gif From gideonc at bgu.ac.il Sun Feb 1 18:38:21 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-05 Physics Colloquium Message-ID: <200902011638.SAA2984595@tzin.bgu.ac.il> Physics Colloquium DATE: 05-02-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Transport in Almost Perfectly Conducting Correlated Electron Systems SPEAKER: Prof. Efrat Shimshoni, Dept. of Physics, Bar Ilan University ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_A/Shimshoni.html Refreshments are served at 3:20pm From Physics at bgu.ac.il Mon Feb 2 10:35:15 2009 From: Physics at bgu.ac.il (Physics@bgu.ac.il) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-04 Nanotechnology Workshop Message-ID: <200902020835.KAA3043958@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 04-02-2009 TIME: 12:00 (noon) PLACE: Chemistry club (Building #29, room 306) TITLE: Soft inorganic materials: An emerging discipline with applications in catalysis and nano-electronics SPEAKER: Ira A. Weinstock , Departments of Chemistry BGU ABSTRACT/COMMENTS: From aaharony at bgu.ac.il Mon Feb 2 13:23:06 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-16 Condensed Matter Seminar Message-ID: <200902021123.NAA3072937@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 16-02-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Amorphization of materials under high pressure SPEAKER: Ori Noked , Physics Department, Ben Gurion University ABSTRACT/COMMENTS: Materials change their properties under pressure. Structural transition is one of the most common phenomena related with high pressure and high temperature conditions. Pressure-induced amorphization (PIA), in which crystalline substances transform into amorphous state under pressure, is an interesting and not fully understood transition. In the lecture I will give a review on high pressure techniques, look into some proposed mechanisms of pressure-induced amorphization, and present a family of perovskites which potentially undergo PIA, as was seen in one of its members. From physics at bgu.ac.il Tue Feb 3 11:45:42 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-04 Nanotechnology Workshop Message-ID: <200902030945.LAA3136900@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 04-02-2009 TIME: 12:00 (noon) PLACE: Chemistry club (Building #29, room 306) TITLE: Soft inorganic materials: An emerging discipline with applications in catalysis and nano-electronics SPEAKER: Ira A. Weinstock , Department of Chemistry BGU ABSTRACT/COMMENTS: Synthetic inorganic chemists have traditionally focused on isolable molecular and solid-sate materials. However, we now recognize that there is a wealth of entirely inorganic supramolecular structures with size domains ranging from the nano to mesoscopic that exist only in solution (Chart1). This area of nanoscience has been largely ignored, primarily because there has been little indication that such a variety of highly organized solution-state structures exist. Now, further developments will require a shift in emphasis from “isolable” to “solution-state” structures. Current programs in our laboratory are designed to advance understanding of these “soft inorganic materials”—an emerging area of supramolecular chemistry—while laying foundations for fundamental contributions to interfacial science, catalysis,and nano-electronics. For example, we recently used cryogenic trapping of solutionstate structures to provide the first reported transmission electron microscopy (cryo-TEM) images of self-assembled monolayers (SAMs) of anions on a colloidal metal(0) nanoparticle (image A; The Journal of the American Chemical Society, 2008). This was achieved using metal-oxygen cluster anions whose physical and electronic properties can be rationally modified at the molecular level. Now, using cryo-TEM, along with complementary solutionstate analytical and spectroscopic methods, we are establishing structure/reactivity relationships for these catalytically active structures. Related new findings include the first observation of anion monolayers on gold nanoparticles, and evidence for the formation of a compositionally and structurally unique class of nano-ordered systems that involve electro-active cluster-anion domains within the organic-ligand shells of monolayer-protected nanoparticles. The latter systems, prepared in collaboration with researchers at the Massachusetts Institute of Technology (MIT), offer unprecedented opportunities for engineering the chemical and electronic properties of nanoscaleordered domains on the surfaces of metal nanoparticles. In other work, we recently discovered two new types of soft inorganic materials, both of which are organized and stabilized by ensembles of identical metal-oxygen cluster anions: cubical “brick and mortar” structures comprised of cluster anions and metal-halide nanoparticles (image B), and entirely inorganic vesicles that feature architectural hierarchies and unprecedented wall structures (image C). Highlights from all the above will be presented. From nano at bgu.ac.il Wed Feb 4 07:52:22 2009 From: nano at bgu.ac.il (Nano) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-04 Reminder Nanotechnology semunar Message-ID: <23F3A9CFD8CD429F98ED8FA3B9DE8DAE@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/gif Size: 29385 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090204/0b57cd26/attachment.gif From dcohen at bgu.ac.il Wed Feb 4 11:52:24 2009 From: dcohen at bgu.ac.il (Doron Cohen) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-04 Physical Chemistry Seminar - CANCELED Message-ID: <49896558.3050507@bgu.ac.il> sending a second time, since it is not in the board. sorry if you got it already. -------- Original Message -------- Subject: 2009-02-04 Physical Chemistry Seminar - CANCELED Date: Tue, 03 Feb 2009 22:39:52 +0200 From: Doron Cohen To: phys-seminars@lists.bgu.ac.il Physical Chemistry Seminar DATE: 04-02-2009 TIME: 4:00pm (Wed) CANCELLED From gideonc at bgu.ac.il Thu Feb 5 16:28:32 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-12 Physics Colloquium Message-ID: <200902051428.QAA3341062@tzin.bgu.ac.il> Physics Colloquium DATE: 12-02-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Can one count the shape of a drum? SPEAKER: Prof. Uzi Smilansky, Dept. of Complex Systems, Weizmann Institute of Science ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_A/Smilansky.html Refreshments are served at 3:20pm From nano at bgu.ac.il Sun Feb 8 09:50:38 2009 From: nano at bgu.ac.il (Nano) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-11 Nanotechnology seminar-Yael Hanein Message-ID: <478D5B9FEC3A4725BF50C0DD6029DF10@estinano> Nanotechnology Seminar, Wednesday 11.2.09, 12:00 building 29, room 307,Chemistry Department seminar room Carbon nanotubes based neurochips Yael Hanein School of Electrical Engineering Tel-Aviv University Abstract: Interfacing biological systems with artificial substrates is of great importance for various applications such as bio-sensing, neural implants and basic investigations of cultured neuronal networks. Accordingly, many methods were developed to control and to study the interaction between cells and surfaces. Vast majority of these approaches consist of chemical modification. In the past several years we have developed a new method for neuronal cell interfacing using nano topography realized by islands of high density fabrics made of carbon nanotubes (CNT). Carbon nanotube coated surfaces are biocompatible, and are excellent surfaces for cell growth and thus are excellent candidates to be used to interface man-made substrates with biological systems. Neurons self-organize on these lithographically defined templates to form interconnected networks with pre-designed geometry and graph connectivity. Our novel approach enables, for the first time, to precisely engineer the geometry as well as the connectivity properties of real neural networks directly on the recording electrode sites, thus paves the way for a wide variety of composite bio-networks. Outstanding recordings capabilities also suggest the suitability of this technology in retinal implant applications. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090208/7d168090/attachment.htm From physics at bgu.ac.il Sun Feb 8 14:27:14 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-11 Nanotechnology Workshop Message-ID: <200902081227.OAA3587255@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 11-02-2009 TIME: 12:00 (noon) PLACE: Chemistry club (Building #29, room 306) TITLE: Carbon nanotubes based neurochips SPEAKER: Yael Hanein, School of Electrical Engineering Tel-Aviv University ABSTRACT/COMMENTS: Interfacing biological systems with artificial substrates is of great importance for various applications such as bio-sensing, neural implants and basic investigations of cultured neuronal networks. Accordingly, many methods were developed to control and to study the interaction between cells and surfaces. Vast majority of these approaches consist of chemical modification. In the past several years we have developed a new method for neuronal cell interfacing using nano topography realized by islands of high density fabrics made of carbon nanotubes (CNT). Carbon nanotube coated surfaces are biocompatible, and are excellent surfaces for cell growth and thus are excellent candidates to be used to interface man-made substrates with biological systems. Neurons self-organize on these lithographically defined templates to form interconnected networks with pre-designed geometry and graph connectivity. Our novel approach enables, for the first time, to precisely engineer the geometry as well as the connectivity properties of real neural networks directly on the recording electrode sites, thus paves the way for a wide variety of composite bio-networks. Outstanding recordings capabilities also suggest the suitability of this technology in retinal implant applications. From aaharony at bgu.ac.il Mon Feb 9 13:01:44 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-23 Condensed Matter Seminar Message-ID: <200902091101.NAA3675667@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 23-02-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Theory of the Quantum Hall Insulator SPEAKER: Roi Levy, Physics Department, Ben Gurion University ABSTRACT/COMMENTS: Experimental studies showed that the transition from the last quantum Hall plateau in the integer quantum Hall effect terminates with a unique insulating phase. This phase is characterized by the divergent of the longitudinal resistivity with decreasing temperature, while the Hall resistivity remains quantized to its value in the last plateau. This is in contradiction to the predictions of the non-interacting electron theory. Therefore, it was suggested that this quantum Hall Insulator phase may be related to incoherent scattering events. We show that by including rare incoherent scattering events the quantum Hall insulator becomes a stable phase. The theory predicts a non-monotonic dependence of the Hall resistance on system size or temperature. Other aspects of the experiments are studied within our approach. From ibar at bgu.ac.il Wed Feb 11 08:50:15 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-17 Lasers Seminar Message-ID: <20090211065019.13B7A146C0B@smtp1.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 17-02-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Experimental quantification of energy transfer mechanisms in Nd doped materials in pursue of more efficient pump-lase schemes SPEAKER: Mr. Sharone Goldring, Electro-Optics Division, Soreq NRC, Yavne, ABSTRACT/COMMENTS: One of the greatest obstacles for achieving efficient high power solid -state lasers with good beam quality is imposed by the heat generated during the pump-lase cycle. This heat tends to create thermal gradient in the laser material and thus causes beam quality degradation. It also degrades the material's physical properties such as thermal conductivity, and causes line broadening and enhanced nonradiative energy transfer routes. Since almost all the energy difference between the pump and the laser photons is transferred to heat, understanding and quantifying the different energy transfer mechanisms along with investigating ways to reduce the thermal load are of great interest. In the presentation, the important energy transfer mechanisms in Nd+3 doped materials will be outlined. Relevant laboratory experiments and results will be presented and discussed. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090211/9d54e9cf/attachment.htm From nano at bgu.ac.il Wed Feb 11 09:01:04 2009 From: nano at bgu.ac.il (Nano) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-11 Reminder! Nanotechnology seminar - Yael Hanein Message-ID: <524E0DDCF35F49FDB3B721A024B3DF10@estinano> Nanotechnology Seminar, Wednesday 11.2.09, 12:00 building 29, room 307,Chemistry Department seminar room Carbon nanotubes based neurochips Yael Hanein School of Electrical Engineering Tel-Aviv University Abstract: Interfacing biological systems with artificial substrates is of great importance for various applications such as bio-sensing, neural implants and basic investigations of cultured neuronal networks. Accordingly, many methods were developed to control and to study the interaction between cells and surfaces. Vast majority of these approaches consist of chemical modification. In the past several years we have developed a new method for neuronal cell interfacing using nano topography realized by islands of high density fabrics made of carbon nanotubes (CNT). Carbon nanotube coated surfaces are biocompatible, and are excellent surfaces for cell growth and thus are excellent candidates to be used to interface man-made substrates with biological systems. Neurons self-organize on these lithographically defined templates to form interconnected networks with pre-designed geometry and graph connectivity. Our novel approach enables, for the first time, to precisely engineer the geometry as well as the connectivity properties of real neural networks directly on the recording electrode sites, thus paves the way for a wide variety of composite bio-networks. Outstanding recordings capabilities also suggest the suitability of this technology in retinal implant applications. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090211/3c15b865/attachment.htm From hbaruch at bgu.ac.il Thu Feb 12 00:55:44 2009 From: hbaruch at bgu.ac.il (hbaruch@bgu.ac.il) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-16 Condensed Matter Seminar Message-ID: <200902112255.AAA3885720@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 16-02-2009 TIME: 15:00 Monday -- note special time PLACE: Physics building (#54) room 207 TITLE: Engineering Proteins for Nanotechnology and Vice-Versa SPEAKER: Dr. Nurit Ashkenasy, Department of Materials Engineering Ben-Gurion University ABSTRACT/COMMENTS: Proteins perform diverse and complex tasks in nature. This diversity, which makes proteins attractive building blocks towards nanotechnology applications, originates from the specific amino acids sequence of each protein that determines their size, shape and functionality. In this talk I will first discuss the design, synthesis and physical measurements of novel peptides (short proteins) and folded proteins as components of electronic devices. I will discuss a peptide-nanotube system with long range charge delocalization, helical proteins that constitute molecular electronics bridges, and bifunctional peptides that drive the assembly of inorganic nanostructures. These studies show that the targeted design of proteins may become a versatile tool in the development of unique electronic conduction systems and fabrication of molecular and electronic devices. Sensitive tools are required for the identification and exploration of proteins. The second part of my talk will thus focus on our recently developed biosensing system. I will show a novel technique, which is based on focused electron beam induced etching, for the fabrication of nanopores. These nanopores will be used for stochastic sensing and identification of proteins, and for studying protein interactions at the single molecule level. From gideonc at bgu.ac.il Thu Feb 12 17:31:32 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2008-02-19 Physics Colloquium Message-ID: <200902121531.RAA3955606@tzin.bgu.ac.il> Physics Colloquium DATE: 19-02-2008 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: LHC and Physics Beyond the Standard Model SPEAKER: Prof. Ehud Duchovni, Dept. of Physics, Weizmann Institute of Science ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_A/Duchovni.html Refreshments are served at 3:20pm From nano at bgu.ac.il Sun Feb 15 09:26:28 2009 From: nano at bgu.ac.il (Nano) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-18 Nanotechnology seminar - T.L. Makarova Message-ID: <5005D28F36E7413086709A1889871FE5@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 18620 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090215/82809ad7/attachment.jpg From physics at bgu.ac.il Sun Feb 15 12:55:16 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-18 Nanotechnology Workshop Message-ID: <200902151055.MAA4179824@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 18-02-2009 TIME: 12:00 (noon) PLACE: Chemistry club (Building #29, room 306) TITLE: On/off magnetism in hydrogenated photopolymerized fullerenes SPEAKER: T. L. Makarova, Department of Physics Umea University, Sweden ABSTRACT/COMMENTS: From physics at bgu.ac.il Tue Feb 17 12:29:00 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Feb 17 13:18:33 2009 Subject: [Phys-seminars] 2009-02-19 Physics Colloquium Message-ID: <200902171029.MAA4366921@tzin.bgu.ac.il> Physics Colloquium DATE: 19-02-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: LHC and Physics Beyond the Standard Model SPEAKER: Prof. Ehud Duchovni, Dept. of Physics Weizmann Institute of Science ABSTRACT/COMMENTS: LHC and Physics Beyond the Standard Model The Standard Model (SM) passed the LEP acid test with flying colors. Yet, it is widely believed that the SM is not the ultimate theory of sub-structure. Numerous models for Physics ?Beyond the SM? (BSM) have been suggested, most of them have one thing in common: They expect the forthcoming LHC accelerator to be powerful enough to unveil the first hints (or more) of these suggested BSM models. I will briefly discuss some of the BSM models, Supersymmetry and Extra-Dimension in particular, and will focus on the preparatory work of the ATLAS collaboration aimed at uncovering various potential experimental signatures of these models. From nano at bgu.ac.il Wed Feb 18 09:51:14 2009 From: nano at bgu.ac.il (Nano) Date: Wed Feb 18 09:50:59 2009 Subject: [Phys-seminars] 2009-02-18 Reminder-Nanotechnology seminar-T.L. Makarova Message-ID: <7453398A77584A09903A3F9AE3924C19@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 18620 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090218/6ba47b54/attachment-0001.jpg From gideonc at bgu.ac.il Thu Feb 19 20:19:05 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Thu Feb 19 20:19:05 2009 Subject: [Phys-seminars] 2009-02-26 Physics Colloquium Message-ID: <200902191819.UAA4605129@tzin.bgu.ac.il> Physics Colloquium DATE: 26-02-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Simulations of self-assembly of cationic lipids and DNA into structured complexes SPEAKER: Dr. Oded Farago, Department of Biomedical Engineering, Ben Gurion University ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_A/Farago.html Refreshments are served at 3:20pm From hbaruch at bgu.ac.il Fri Feb 20 13:10:06 2009 From: hbaruch at bgu.ac.il (hbaruch@bgu.ac.il) Date: Fri Feb 20 13:10:09 2009 Subject: [Phys-seminars] 2009-02-23 Condensed Matter Seminar Message-ID: <200902201110.NAA4649774@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 23-02-2009 TIME: 15:00 Monday -- note special time PLACE: Physics building (#54) room 207 TITLE: Graphene: a new bridge between condensed matter physics and quantum electrodynamics. SPEAKER: Prof. Mikhail Katsnelson, Radboud University of Nijmegen, The Netherlands ABSTRACT/COMMENTS: Charge carriers in graphene, recently discovered exactly two- dimensional allotrope of carbon, are masless chiral Dirac fermions with the velocity three hundred times smaller than the velocity of light. This established new and unexpected relations between condensed matter physics and quantum electrodynamics and opens a way to probe some effects which are hardly reachable in high-enery physics (Klein tunneling, vacuum breakdown near supercritical charge, etc.). Minimal metallic conductivity and universal optical conductivity are another specific properties of graphene related with its peculiar electron spectrum. From idobd at bgu.ac.il Tue Feb 24 14:06:21 2009 From: idobd at bgu.ac.il (idobd@bgu.ac.il) Date: Tue Feb 24 14:06:23 2009 Subject: [Phys-seminars] 2009-03-02 Particles and Fields Seminar Message-ID: <200902241206.OAA5019206@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 02-03-2009 TIME: 10:00am (Mon) PLACE: Physics building (#54) room 207 TITLE: TBA SPEAKER: Alex Kovner, University of Connecticut ABSTRACT/COMMENTS: There is a chance that the seminar will be cancelled - watch out for further announcements. From idobd at bgu.ac.il Tue Feb 24 14:17:37 2009 From: idobd at bgu.ac.il (idobd@bgu.ac.il) Date: Tue Feb 24 14:17:37 2009 Subject: [Phys-seminars] 2009-03-09 Particles and Fields Seminar Message-ID: <200902241217.OAA5051543@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 09-03-2009 TIME: 10:00am (Mon) PLACE: Physics building (#54) room 207 TITLE: On the entropic boundary law in loop quantum gravity and BF theory. SPEAKER: Daniel R. Terno, Centre for Quantum Computer Technology Faculty of Science Macquarie University Sydney NSW, Australia ABSTRACT/COMMENTS: It is commonly accepted that some form of a holographic principle holds in nature, and a lot of effort goes into its derivation from the first principles. In the framework of loop quantum gravity (LQG) we generalize boundary state counting to a full bulk state counting . We show how to compute the bulk entropy of a bounded region of space (the “black hole”) with fixed boundary conditions. This allows to study in detail the relationship between the entropy and the boundary area and to identify a holographic regime for LQG where the leading order of the entropy scales with the area. One of the conclusions is that a holography is not a necessary feature of the theory and could appear only from dynamical considerations. On the other hand, topological theories allow for a controlled introduction of local degrees of freedom in the form of topological defects. We compute the entropy of a closed bounded region of space for pure 3d Riemannian gravity formulated as a topological BF theory for the gauge group SU(2) and show its holographic behavior [2]. More precisely, we consider a fixed graph embedded in space and study the flat connection spin network state without and with particle-like topological defects. We regularize and compute the entanglement for a bipartite splitting of the graph and show it scales at leading order with the number of vertices on the boundary (or equivalently with the number of loops crossing the boundary), while the introduction of the defects in the exterior or interior bulk does not affect the entropy. These results apply to BF theory with any compact gauge group in any space-time dimension. From nano at bgu.ac.il Tue Mar 3 11:26:13 2009 From: nano at bgu.ac.il (Nano) Date: Tue Mar 3 11:26:00 2009 Subject: [Phys-seminars] 2009-03-04 special seminar Message-ID: <1E00E89D5EC24FA3A3A9963615AEEC82@estinano> Special Seminar Ben-Gurion University of the Negev Department of Chemistry and Nanotechnology Institute Wednesday, March 4, 2009 Time: 15:00 Bldg. 29 Room 307 (Chemistry seminar room) Dr. Taleb Mokari "Synthesis of Nanostructures for Renewable Energy" ???? ???????! -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090303/c72e43af/attachment.htm From idobd at bgu.ac.il Thu Mar 19 12:31:38 2009 From: idobd at bgu.ac.il (idobd@bgu.ac.il) Date: Thu Mar 19 12:31:39 2009 Subject: [Phys-seminars] 2009-03-30 Particles and Fields Seminar Message-ID: <200903191031.MAA7267598@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 30-03-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Domain walls with non-Abelian clouds SPEAKER: Norisuke Sakai, Department of Mathematics, Tokyo Woman\'s Christian University ABSTRACT/COMMENTS: Similarities and differences of domain walls and D-branes are addressed. Domain walls in U(N) gauge theories, coupled to Higgs scalar fields with degenerate masses, are shown to possess normalizable non-Abelian Nambu-Goldstone(NG) modes, which we call non-Abelian clouds. We construct the moduli space metric and its Kahler potential of the effective field theory on the domain walls, by focusing on two models: a U(1) gauge theory with several charged Higgs fields, and a U(N) gauge theory with 2N Higgs fields in the fundamental representation. We find that non-Abelian clouds spread between two domain walls. In the latter model we find that when all walls coincide SU(N)_L x SU(N)_R x U(1) symmetry is broken down to SU(N)_V, and U(N)_A NG modes and the same number of quasi-NG modes are localized on the wall. When n walls separate, off diagonal elements of U(n) NG modes have wave functions spreading between two separated walls (non-Abelian clouds), whereas some quasi-NG modes turn to NG bosons as a result of further symmetry breaking U(n)_V -> U(1)_V^n. In the case of 4+1 dimensional bulk, we can dualize the effective theory to the supersymmetric Freedman-Townsend model of non-Abelian 2-form fields. From idobd at bgu.ac.il Thu Mar 19 12:36:01 2009 From: idobd at bgu.ac.il (idobd@bgu.ac.il) Date: Thu Mar 19 12:36:01 2009 Subject: [Phys-seminars] 2009-03-30 Particles and Fields Seminar Message-ID: <200903191036.MAA7251152@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 30-03-2009 TIME: 1p.m. (Mon) PLACE: Physics building (#54) room 207 TITLE: CMB and Fundamental Physics (at 1 pm!) SPEAKER: Meir Shimon, UC San Diego ABSTRACT/COMMENTS: The small temperature anisotropy and polarization of the cosmic microwave background (CMB) radiation have been the target of numerous earth-based, baloon-born and satellite missions in the last two decades. Upcoming CMB experiments, equipped with higher sensitivity and angular resolution, will provide us with higher fidelity probes of the CMB polarization state and secondaries, such as comptonization of the CMB by the Sunyaev-Zeldovich (SZ) effect. The CMB is essentially a snapshot of the universe at recombination and carries a valuable information about a much earlier process, cosmological inflation. Secondary effects that took place much later, at redshifts of a few, such as gravitational lensing of the CMB by the intervening large scale structure and the SZ effect, provide us with cosmological bounds on neutrino masses and chemical potentials as well as the dark energy equation-of-state. Rotation of the CMB polarization-plane, due to non-standard coupling of the electromagnetic field to other scalar fields, \'cosmological birefringence\', can be used to set limits on the axion mass and coupling to electromagnetic fields. Finally, spectral distortions in the SZ effect can be used to constrain non-standard scalings of the CMB temperature with redshift. From nano at bgu.ac.il Sun Mar 22 11:28:36 2009 From: nano at bgu.ac.il (Nano) Date: Sun Mar 22 11:28:32 2009 Subject: [Phys-seminars] 2009-03-29 - Serdar Sariciftci - Nanotechnology special seminar Message-ID: <18A9A55E98DE4E2BB3AFA40ADCB9A50B@estinano> Nanotechnology Special Seminar, Sunday 29.3.09, 12:00 building 29, room 307,Chemistry Department seminar room Organic Photovoltaic Devices: >From Electricity to Synthetic Fuels Serdar Sariciftci Linzer Institut f?r organische Solarzellen (LIOS) Physikalische Chemie Johannes Kepler Universit?t Linz AUSTRIA Website: http://www.ipc.uni-linz.ac.at/Staff/CV.html -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090322/2c65391c/attachment-0001.htm From nano at bgu.ac.il Thu Mar 26 14:55:44 2009 From: nano at bgu.ac.il (Nano) Date: Thu Mar 26 14:55:43 2009 Subject: [Phys-seminars] 2009-03-29 Reminder Nanotechnology seminar Message-ID: <48558380CCAA4DEB986881AAA8459628@estinano> Personal meetings with Prof Serdar Sariciftci can be coordinated wit Dr. Iris Visoly Nanotechnology Special Seminar, Sunday 29.3.09, 12:00 building 29, room 307,Chemistry Department seminar room Organic Photovoltaic Devices: From Electricity to Synthetic Fuels Serdar Sariciftci Linzer Institut f?r organische Solarzellen (LIOS) Physikalische Chemie Johannes Kepler Universit?t Linz AUSTRIA Abstract Organic photovoltaic diodes (OPVs) and organic solar cells are reviewed. The different energy and electron transfer mechanisms of energy harvesting as well as energy conversion are discussed. Pure organic photovoltaic devices and organic/inorganic hybrid devices are comparatively explained. This talk gives an overview of materials? aspect, charge-carrier-transport, and device physics of such organic diodes. Furthermore, the use of solar photoenergy to reduce CO2 into hydrocarbon based synthetic fuels is introduced. Such artificial photosynthesis type fuel production can simultaneously solve the energy storage and energy transport problems of photovoltaic electricity. Website: http://www.ipc.uni-linz.ac.at/Staff/CV.html -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090326/c8c4bf99/attachment.htm From aaharony at bgu.ac.il Mon Mar 30 11:23:00 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Mon Mar 30 11:23:00 2009 Subject: [Phys-seminars] 2009-04-20 Condensed Matter Seminar Message-ID: <200903300823.LAA8311532@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 20-04-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Geometric Frustration in Buckled Colloidal Monolayers SPEAKER: Yair Shokef, Department of Physics of Complex Systems - Weizmann Institute of Science ABSTRACT/COMMENTS: We study geometric frustration in a quasi-two-dimensional system comprised of macroscopic constituents. Closely packed colloidal spheres confined between parallel walls self-assemble into a triangular lattice. For walls separated by slightly more than a single sphere diameter the monolayer buckles out of the plane to gain free volume by maximizing inter-particle distances. Like antiferromagnetic Ising spins, each sphere can be up or down and nearest neighbors prefer being at opposite states. We use microgel spheres with a temperature-sensitive diameter to tune the packing density which in turn sets the strength of the effective antiferromagnetic interaction between neighboring spheres. The micrometer length-scale of the spheres enables direct visualization of the \'spin\' dynamics at the single-particle level. Our joint experimental and theoretical work reveals glassy dynamics which are governed by in-plane lattice distortions that partially relieve frustration and produce ground states with zigzagging stripes and subextensive entropy. The results we obtain for the structure and dynamics of this soft-matter system shed light on the nature of excitations and on the role of elasticity in geometrically-frustrated systems. From physics at bgu.ac.il Mon Apr 6 12:37:22 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Mon Apr 6 12:37:24 2009 Subject: [Phys-seminars] 2009-04-20 Particles and Fields Seminar Message-ID: <200904060937.MAA8959859@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 20-04-2009 TIME: 10:00am (Mon) PLACE: Physics building (#54) room 207 TITLE: \"Hamiltonian Dynamics in General Relativity\" SPEAKER: Larry Horwitz , Physics Department Tel Aviv University ABSTRACT/COMMENTS: From ibar at bgu.ac.il Mon Apr 13 10:30:06 2009 From: ibar at bgu.ac.il (ilana) Date: Mon Apr 13 10:30:21 2009 Subject: [Phys-seminars] 2009-04-21 Lasers Seminar Message-ID: <20090413073017.EDC66146C73@smtp1.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 21-04-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Evolutionary Dynamics in Time-Varying Environments in the Quasispecies Model SPEAKER: Mr. Pavel Gorodetsky, Department of Physics, Ben Gurion University of the Negev ABSTRACT/COMMENTS: During the course of evolution, living organisms have developed several mechanisms to maintain the integrity of their genomes. These mechanisms can both repair errors that rise from the error-prone replication of DNA (mutations), as well as damage to DNA due to external factors, such as radiation. These mechanisms act at the organismic level, that is, they are activated inside an individual within the population. Sexual reproduction may also be considered as a means of maintaining the integrity of the genome at the population level, as sexual reproduction involves interaction between individuals. We study two mechanisms and their effect on the adaptability of populations in dynamic environments: (1) The MisMatch Repair mechanism (MMR), which lowers the effective mutation rate during replication; (2) Sexual reproduction, which may purge deleterious mutations in static environments or speed up adaptation in dynamic environments. The first part of our work models the MMR mechanism. We were able to derive an analytically solvable model in a point-mutation limit, which correctly predicts the fraction of viable mutators in a population as a function of mutation rate, efficiency of the repair mechanism, and the properties of the dynamical fitness landscape. In the second part, we model the asexual and sexual reproduction pathways in S. cerevisiae (Baker's yeast). We were able to show that sexual replication can both purge deleterious mutations in a static environment, as well as lead to faster adaptation in a dynamic environment. This implies that sex can serve a dual role, which is in sharp contrast to previous theories. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090413/f17f5a7e/attachment.htm From nano at bgu.ac.il Thu Apr 16 13:52:54 2009 From: nano at bgu.ac.il (Nano) Date: Thu Apr 16 13:53:04 2009 Subject: [Phys-seminars] 2009-04-22 Nanotechnology seminar-J M Fernandez Message-ID: <25A524B6D0C8457FB3AD3F7D156AB55D@estinano> Nanotechnology Seminar, Wednesday 22.4.09, 12:00 building 29, room 307,Chemistry Department seminar room Force-clamp spectroscopy of single proteins Julio M. Fernandez, Columbia University, New York Abstract: We aim to understand how mechanical forces, over the full biological spectrum, affect the dynamics and chemistry of proteins. Using molecular biology techniques, we engineered tandem modular proteins that are made of identical repeats of a protein of interest. These polyproteins act as handles for atomic force microscopes, without the need for linkers or special attachment chemistry. When such polyproteins are extended by an AFM, their force properties are unique mechanical fingerprints that unambiguously distinguish them from the more frequent non-specific events that plague single molecule studies. Our initial experiments were done by extending polyproteins at constant velocity, resulting in the now familiar sawtooth pattern traces of unfolding. We made observations that could never have been obtained from bulk biochemistry. For example, that while under a stretching force proteins unfold following mechanical hierarchies, explaining the mechanical architecture of large elastic proteins such as titin and fibronectin. We also discovered that the mechanical stability of a protein depends on the direction of the applied force, revealing that proteins have intrinsic "Achilles heels" for unfolding, which may play a role in their degradation. However, in our early experiments, the variables of force, length and loading rate changed simultaneously over wide ranges, and thus yielded only qualitative results. We solved these problems by introducing force-clamp AFM. With this approach, the length of an extending polyprotein is measured while the pulling force is actively kept constant by negative feedback control. Akin to the use of voltage-clamp techniques to study ion channels, the force-clamp technique combined with polyprotein engineering has become a powerful approach to study proteins. We have investigated the force-dependency of protein folding, unfolding and of chemical reactions. From the force-dependence, we extract features of the transition state of these reactions that reveal underlying molecular mechanisms. For example, we found that the distance to the transition state of protein unfolding follows the size of the solvent molecules, implicating them in the transition state structure. Using force pulses, we drove a single protein to a highly extended state, and then upon quenching the force observed how the protein folded (1). Observing a folding reaction over regions hitherto unexplored, uncovered a rich diversity of trajectories of protein folding that had been hidden in bulk experiments. The observations support statistical theories of folding that predicted the absence of defined states and preferred pathways. Perhaps the most striking use of force-clamp spectroscopy so far has been in the study of the effect of force on a chemical reaction. While mortars and pestles have been used for thousands of years to catalyze chemical reactions, it had never been possible to examine a molecule undergoing a chemical reaction while placed under a calibrated and vectorially defined force. We applied a constant stretching force to engineered disulfide bonds and measured their rate of reduction by small molecules and enzymes. These experiments captured the effect of a mechanical force on the rotation and elongation of the disulfide bond as it reached the transition state within the active site of the thioredoxin enzyme (2). More recently, we have observed that these sub-?ngstr?m scale rearrangements, where enzymatic chemistry takes place, are sensitive to the evolutionary origins of the thioredoxin enzyme. Thus, force-clamp AFM, with its remarkable ability to manipulate short recombinant proteins, has become a useful probe of protein dynamics, allowing us to sense conformational changes down to the sub-?ngstr?m scale. Our data will help guide the development of new theories on areas such as enzyme catalysis, the statistical dynamics of a folding polymer and ab initio studies of a chemical reaction while placed under a stretching force; of common occurrence in nature. 1.- Fernandez, J.M. and Li, H. B. Force-clamp spectroscopy monitors the folding trajectory of a single protein (2004), Science, 303: 1674-1678 2.- Wiita et al, (2007) Probing the chemistry of thioredoxin catalysis with force. Nature, 450:124-7. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090416/d1871f50/attachment-0001.htm From gideonc at bgu.ac.il Sun Apr 19 12:23:18 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Sun Apr 19 12:23:21 2009 Subject: [Phys-seminars] 2009-04-23 Physics Colloquium Message-ID: <200904190923.MAA10126833@tzin.bgu.ac.il> Physics Colloquium DATE: 23-04-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Dephasing and noise in weakly-coupled Bose-Einstein condensates SPEAKER: Dr. Amichay Vardi, Deptartment of Chemistry, Ben Gurion University ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_B\\Vardi.html Refreshments are served at 3:20pm From aaharony at bgu.ac.il Mon Apr 20 11:20:56 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Mon Apr 20 11:20:57 2009 Subject: [Phys-seminars] 2009-05-04 Condensed Matter Seminar Message-ID: <200904200820.LAA9295952@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 04-05-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Experimental Study of Electrical Parameters of YBCO Coated Conductors SPEAKER: Noam Tal, Physics Deopartment, Ben Gurion University ABSTRACT/COMMENTS: At present, the YBCO coated conductors have the most advanced manufacturing technology and will be primarily used in the first large-scale power applications of high-temperature superconductors. These conductors represent a composite tape where YBCO layer is deposited on a metallic substrate and covered by a stabilizing silver layer. The most important characteristic determining the effectiveness of the AC devices based on coated conductors is AC losses due to external magnetic field or transport current. To reduce these losses, the silver and YBCO layers are striated to a number of strips. The problem of AC loss evaluation in this composite conductor is a crucial issue for the development of superconducting devices for power applications at alternating currents. AC loss values determine ranges of the rated current and magnetic fields for superconducting devices such as cryogenic equipment and economical gain. To evaluate correctly AC losses, knowledge of basic electrical parameters of a coated conductor is required. This thesis is focused on the experimental study of electrical parameters of YBCO coated conductors: silver layer resistance, interfilament resistance and interlayer resistance (the last determines the thermal stability of the conductor). An experimental setup for DC and AC measurements was developed and built. The electrical parameters were measured under both DC and AC conditions. The important result is that interfilament resistance is much higher than the generally used at the coupling loss estimation. Obtained results were used for loss evaluation in coated conductors operated in high magnetic fields and with transport current. Dependences of all the components of losses: hysteresis, coupling and eddy current loss, on magnetic field, frequency and twist length were studied. Based on this study, optimization of twist length of a coated conductor was performed. The total loss of the optimized coated conductor with the twist length of 0.5 m operated in the field of 1 T at the frequency of 400 Hz is evaluated as 110 W/m. From aaharony at bgu.ac.il Mon Apr 20 13:26:21 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Mon Apr 20 13:26:21 2009 Subject: [Phys-seminars] 2009-05-11 Condensed Matter Seminar Message-ID: <200904201026.NAA10212453@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 11-05-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Title: Electric transport through a single nanoparticle - unique charging effects in a metallic quantum dot SPEAKER: Professor Aviad Frydman , Bar Ilan University ABSTRACT/COMMENTS: We have developed a novel method for measuring the conductance versus gate voltage of a metallic nanoparticle having variable coupling to large electric leads. These systems exhibit periodic Coulomb blockade peaks which strongly decrease in amplitude as the dot-lead coupling is increased. At the same time an additional set of periodic peaks appear and become the dominant feature for strong coupling. For a specific coupling, the coulomb blockade peaks shift from one period to another as a function of applied source-drain voltage across the dot. We discuss possible scenarios for these results. From silon at bgu.ac.il Mon Apr 20 16:17:20 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Mon Apr 20 16:17:21 2009 Subject: [Phys-seminars] 2009-04-27 Particles and Fields Seminar Message-ID: <200904201317.QAA10220390@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 27-04-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Some dark matter tidbits SPEAKER: Shmuel Nussinov, Tel Aviv Univesity ABSTRACT/COMMENTS: I will discuss the Dama annual signal - the idea of seeing there and or in other single crystal detectors a signal paking TWICE EVERY SIDERAL DAY, also Ill describe briefly the phenomenology of a new class of models for DM which attempt to explain some positron/electron exccesses as well. From ibar at bgu.ac.il Tue Apr 21 10:55:23 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Apr 21 10:55:50 2009 Subject: [Phys-seminars] 2009-04-27 Lasers Seminar Message-ID: <20090421075542.1A182146C0E@smtp1.bgu.ac.il> ANNOUNCEMENT==> Joint Lasers and Homeland Security Research Institute Seminar DATE: 27-04-2009 TIME: 3:30pm (Mon) PLACE: Building (#29) room 307 Chemistry Department Seminar Room TITLE: Photonic Sensors for Explosive Detection SPEAKER: Prof. Wolfgang Schade Fraunhofer Heinrich-Hertz-Institut, Technische Universit?t Clausthal, D-38640 Goslar, Germany ABSTRACT/COMMENTS: The detection of improvised explosive devices (IEDs) in conflict areas as well as the threat posed on common welfare by terrorist attempts in creasingly became focal points of interest in recent years. Novel photonic sensor devices applying evanescent field spectroscopy and nano-dimensioned waveguides in combination with miniaturized lasers such as microchip- and quantum cascade lasers reveal entirely new possibilities for in situ and real-time diagnostics. In this context evanescent-field laser spectroscopy is a very promising method for extreme sensitive detection of low-vapor pressure explosives, e.g. TNT (Trinitrotoluene). TNT is highly toxic and carcinogenic and the detection of this explosive is very difficult due to its extreme low vapour pressure, resulting in concentrations down to the ppt level. A new concept is developed which allows the identification of TNT by using a fibre optic evanescent-field-sensor that has been coated with a specially engineered receptor film (triphenylene-based ketals). This opens new possibilities for miniaturized and highly sensitive photonic sensor devices, e.g., for application on robotic platforms. A second photonic sensor device is developed applying photoacoustic spectroscopy. Instead of a conventional photoacoustic cell just a simple quartz tuning fork is used as sensor element. Miniaturized laser technology and fibre optics enable engineering a smart handheld sensor, e.g., for the detection of TATP (tri-acetone tri-peroxide). A third approach is pulsed laser fragmentation (PLF) in combination with high-resolution mid-infrared laser absorption spectroscopy which offers new possibilities for sensitive and selective stand-off analysis of surface contaminations under real-time operation conditions. The detection of NOx production rates emitted from contaminated surfaces after interaction with an infrared PLF laser beam allows analysis of different surface contaminations, e.g., distinguishing between energetic and non-energetic materials but also between molecules with similar atomic composition. The concepts and miniaturization of such technologies are discussed. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090421/bf8cfc53/attachment.htm From nano at bgu.ac.il Wed Apr 22 09:34:02 2009 From: nano at bgu.ac.il (Nano) Date: Wed Apr 22 09:34:13 2009 Subject: [Phys-seminars] 2009-04-22 Reminder Nanotechnology seminar - notice the change in place Message-ID: <01F554481D9248A6B3DC6059F40E0D12@estinano> Nanotechnology Seminar, Wednesday 22.4.09, 12:00 building 33, room 102 Force-clamp spectroscopy of single proteins Julio M. Fernandez, Columbia University, New York Abstract: We aim to understand how mechanical forces, over the full biological spectrum, affect the dynamics and chemistry of proteins. Using molecular biology techniques, we engineered tandem modular proteins that are made of identical repeats of a protein of interest. These polyproteins act as handles for atomic force microscopes, without the need for linkers or special attachment chemistry. When such polyproteins are extended by an AFM, their force properties are unique mechanical fingerprints that unambiguously distinguish them from the more frequent non-specific events that plague single molecule studies. Our initial experiments were done by extending polyproteins at constant velocity, resulting in the now familiar sawtooth pattern traces of unfolding. We made observations that could never have been obtained from bulk biochemistry. For example, that while under a stretching force proteins unfold following mechanical hierarchies, explaining the mechanical architecture of large elastic proteins such as titin and fibronectin. We also discovered that the mechanical stability of a protein depends on the direction of the applied force, revealing that proteins have intrinsic "Achilles heels" for unfolding, which may play a role in their degradation. However, in our early experiments, the variables of force, length and loading rate changed simultaneously over wide ranges, and thus yielded only qualitative results. We solved these problems by introducing force-clamp AFM. With this approach, the length of an extending polyprotein is measured while the pulling force is actively kept constant by negative feedback control. Akin to the use of voltage-clamp techniques to study ion channels, the force-clamp technique combined with polyprotein engineering has become a powerful approach to study proteins. We have investigated the force-dependency of protein folding, unfolding and of chemical reactions. From the force-dependence, we extract features of the transition state of these reactions that reveal underlying molecular mechanisms. For example, we found that the distance to the transition state of protein unfolding follows the size of the solvent molecules, implicating them in the transition state structure. Using force pulses, we drove a single protein to a highly extended state, and then upon quenching the force observed how the protein folded (1). Observing a folding reaction over regions hitherto unexplored, uncovered a rich diversity of trajectories of protein folding that had been hidden in bulk experiments. The observations support statistical theories of folding that predicted the absence of defined states and preferred pathways. Perhaps the most striking use of force-clamp spectroscopy so far has been in the study of the effect of force on a chemical reaction. While mortars and pestles have been used for thousands of years to catalyze chemical reactions, it had never been possible to examine a molecule undergoing a chemical reaction while placed under a calibrated and vectorially defined force. We applied a constant stretching force to engineered disulfide bonds and measured their rate of reduction by small molecules and enzymes. These experiments captured the effect of a mechanical force on the rotation and elongation of the disulfide bond as it reached the transition state within the active site of the thioredoxin enzyme (2). More recently, we have observed that these sub-?ngstr?m scale rearrangements, where enzymatic chemistry takes place, are sensitive to the evolutionary origins of the thioredoxin enzyme. Thus, force-clamp AFM, with its remarkable ability to manipulate short recombinant proteins, has become a useful probe of protein dynamics, allowing us to sense conformational changes down to the sub-?ngstr?m scale. Our data will help guide the development of new theories on areas such as enzyme catalysis, the statistical dynamics of a folding polymer and ab initio studies of a chemical reaction while placed under a stretching force; of common occurrence in nature. 1.- Fernandez, J.M. and Li, H. B. Force-clamp spectroscopy monitors the folding trajectory of a single protein (2004), Science, 303: 1674-1678 2.- Wiita et al, (2007) Probing the chemistry of thioredoxin catalysis with force. Nature, 450:124-7. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090422/7026d0a9/attachment-0001.htm From gideonc at bgu.ac.il Thu Apr 23 18:40:46 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Thu Apr 23 18:40:49 2009 Subject: [Phys-seminars] 2009-04-30 Physics Colloquium Message-ID: <200904231540.SAA10530444@tzin.bgu.ac.il> Physics Colloquium DATE: 30-04-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: On The Geometrical properties of plasmonic lattices SPEAKER: Prof. Zeev Valy Vardeny, Department of Physics, University of Utah ABSTRACT/COMMENTS: For abstract please enter the link below: http:\\\\physweb.bgu.ac.il\\EVENTS\\COLLOQ\\collq09_B\\Vardeny.html Refreshments are served at 3:20pm From gideonc at bgu.ac.il Thu Apr 23 18:58:17 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Thu Apr 23 18:58:20 2009 Subject: [Phys-seminars] 2009-04-30 Physics Colloquium Message-ID: <200904231558.SAA10518717@tzin.bgu.ac.il> Physics Colloquium DATE: 30-04-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: On The Geometrical properties of plasmonic lattices SPEAKER: Prof. Zeev Valy Vardeny, Department of Physics, University of Utah ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_B/Vardeny.html Refreshments are served at 3:20pm From physics at bgu.ac.il Sun Apr 26 11:26:41 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Sun Apr 26 11:26:40 2009 Subject: [Phys-seminars] 2009-05-03 Special Physics Colloquium Message-ID: <200904260826.LAA10795079@tzin.bgu.ac.il> Special Physics Colloquium DATE: 03-05-2009 TIME: 3:30pm (Sun) PLACE: Physics building (#54) room 207 TITLE: >From area laws to the simulation of quantum systems SPEAKER: Prof. Martin B Plenio, Director, Quantum Information Programme Institute for Mathematical Sciences Imperial College London ABSTRACT/COMMENTS: Physical interactions in quantum many-body systems are typically local: Individual constituents interact mainly with their few nearest neighbors. This locality of interactions is inherited by a decay of correlation functions, but also reflected by scaling laws of the en- tanglement entropy of ground states. This entropy of the reduced state of a subregion often merely grows like the boundary area of the subregion, and not like its volume, in sharp contrast to an ex- tensive behavior. Such \"area laws\'\' for the entanglement entropy and related quantities have received considerable attention in re- cent years. They emerge in several seemingly unrelated fields, in the context of black hole physics, quantum information science, and quantum many-body physics. In this talk I will present some recent results on this topic. Center stage is taken by rigorous results on lattice models in one and higher spatial dimensions and the connection between the entanglement content of states and the possibility of their efficient numerical simulation. From ibar at bgu.ac.il Sun Apr 26 17:38:37 2009 From: ibar at bgu.ac.il (ilana) Date: Sun Apr 26 17:38:40 2009 Subject: [Phys-seminars] 2009-04-27 Lasers Seminar Message-ID: <20090426143836.A75FE146C15@smtp2.bgu.ac.il> Note the change of the regular date and place! ANNOUNCEMENT==> Special Joint Lasers and Homeland Security Research Institute Seminar DATE: 27-04-2009 TIME: 3:30pm (Mon) PLACE: Building (#29) room 307 Chemistry Department Seminar Room TITLE: Photonic Sensors for Explosive Detection SPEAKER: Prof. Wolfgang Schade Fraunhofer Heinrich-Hertz-Institut, Technische Universit?t Clausthal, D-38640 Goslar, Germany ABSTRACT/COMMENTS: The detection of improvised explosive devices (IEDs) in conflict areas as well as the threat posed on common welfare by terrorist attempts in creasingly became focal points of interest in recent years. Novel photonic sensor devices applying evanescent field spectroscopy and nano-dimensioned waveguides in combination with miniaturized lasers such as microchip- and quantum cascade lasers reveal entirely new possibilities for in situ and real-time diagnostics. In this context evanescent-field laser spectroscopy is a very promising method for extreme sensitive detection of low-vapor pressure explosives, e.g. TNT (Trinitrotoluene). TNT is highly toxic and carcinogenic and the detection of this explosive is very difficult due to its extreme low vapour pressure, resulting in concentrations down to the ppt level. A new concept is developed which allows the identification of TNT by using a fibre optic evanescent-field-sensor that has been coated with a specially engineered receptor film (triphenylene-based ketals). This opens new possibilities for miniaturized and highly sensitive photonic sensor devices, e.g., for application on robotic platforms. A second photonic sensor device is developed applying photoacoustic spectroscopy. Instead of a conventional photoacoustic cell just a simple quartz tuning fork is used as sensor element. Miniaturized laser technology and fibre optics enable engineering a smart handheld sensor, e.g., for the detection of TATP (tri-acetone tri-peroxide). A third approach is pulsed laser fragmentation (PLF) in combination with high-resolution mid-infrared laser absorption spectroscopy which offers new possibilities for sensitive and selective stand-off analysis of surface contaminations under real-time operation conditions. The detection of NOx production rates emitted from contaminated surfaces after interaction with an infrared PLF laser beam allows analysis of different surface contaminations, e.g., distinguishing between energetic and non-energetic materials but also between molecules with similar atomic composition. The concepts and miniaturization of such technologies are discussed. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090426/ca72a6ca/attachment.htm From ibar at bgu.ac.il Tue Apr 28 08:12:05 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Apr 28 08:12:09 2009 Subject: [Phys-seminars] 2009-05-05 Lasers Seminar Message-ID: <20090428051206.6E86E146C39@smtp1.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 05-05-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Single-Molecule-Based Approaches for Probing Biochemical Reactions: From Protein-DNA specificity to Virus-Host Interactions SPEAKER: Dr. Eli Rothenberg, Department of Physics, University of Illinois - Urbana, Illinois, USA ABSTRACT/COMMENTS: Single-molecule (sm) microscopy and spectroscopy are powerful techniques that allow probing of specific features of biomolecules and biochemical reactions that are otherwise masked in ensemble measurements. In my talk I will introduce the concept of single-molecule-based approaches and the ways they can be used to study biological systems, both in-vitro and in-vivo. First, I will describe our in-vitro FRET-based single-molecule studies of a DNA-metabolism enzyme, the MCM helicase and its DNA substrate specificity. Next, I will discuss ongoing efforts for studying virus-host interaction in-vivo, where single-molecule-based approaches have enabled us to accurately probe the virus-host target-finding process of Lambda-Phage on E. coli in real time. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090428/86a47472/attachment.htm From silon at bgu.ac.il Thu Apr 30 12:23:35 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Thu Apr 30 12:23:35 2009 Subject: [Phys-seminars] 2009-05-04 Particles and Fields Seminar Message-ID: <200904300923.MAA11166249@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 04-05-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Do Galaxies and Black Holes Shed Mass? SPEAKER: Doron Chelouche, Canadian Institute for Theoretical Astrophysics, Toronto, Canada ABSTRACT/COMMENTS: From silon at bgu.ac.il Thu Apr 30 12:24:30 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Thu Apr 30 12:24:30 2009 Subject: [Phys-seminars] 2009-05-04 Astrophysics and Cosmology Seminar Message-ID: <200904300924.MAA11134929@tzin.bgu.ac.il> Astrophysics and Cosmology Seminar DATE: 04-05-2009 TIME: 10:00 am (Mon) PLACE: Physics building (#54) room 207 TITLE: Do Galaxies and Black Holes Shed Mass? SPEAKER: Doron Chelouche , Canadian Institute for Theoretical Astrophysics, Toronto, Canada ABSTRACT/COMMENTS: From nano at bgu.ac.il Thu Apr 30 18:14:45 2009 From: nano at bgu.ac.il (Nano) Date: Thu Apr 30 18:15:04 2009 Subject: [Phys-seminars] 2009-05-06 Nanotechnology seminar-D. Danino Message-ID: <0E0077B9D259456A93DFBF515D9CFCD8@estinano> Nanotechnology Seminar, Wednesday 6.5.2009, 12:00 building 29, room 307,Chemistry Department seminar room Insight into the Unusual Self-Assembly of Bioinspired Amphiphiles into Ribbons and Nanotubes Dganit Danino Department of Biotechnology and Food Engineering Technion, Israel Institute of Technology Abstract: The growing field of nanotechnology has historically emphasized the ?bottom-up? approach, in which precursor molecules are able to assemble spontaneously (?self-assemble?) into structures of interest when placed in water or other solvents. This ability to self-assemble is inherent in biomolecules such as proteins, peptides and lipids, as well as in synthetic amphiphiles, i.e., surfactants and detergents. Although self-assembly has had a long history, there are certain types of self-assembled structures that are much less understood than others. One such class of structures comprises 1-dimensional (1-D) typically bilayered aggregates, which encompass twisted and helical ribbons, and nanotubes. These nanostructures could find many analogous applications to CNTs, which include encapsulation and controlled release, sensors for biomolecules, and as templates for construction of metal rods and inorganic (e.g., silica) hollow tubules. Curved ribbons and nanotubes are formed only by certain amphiphilic molecules, not all, and are stable only under a specific set of conditions. They are especially ubiquitous when the amphiphiles have amino-acid or sugar headgroups. In other classes of amphiphiles, flat ribbons and vesicles form. The talk will focus on our recent studies exploring the relations between the molecular structure and the self-assembly mechanism, and the factors driving the formation of these nanostructured liquids. Special emphasize will be given to the application of advanced cryogenic electron microscopy methods in these studies. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090430/6e4351cf/attachment.htm From silon at bgu.ac.il Sun May 3 11:05:06 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Sun May 3 11:05:07 2009 Subject: [Phys-seminars] 2009-05-06 Astrophysics and Cosmology Seminar Message-ID: <200905030805.LAA11434906@tzin.bgu.ac.il> Astrophysics and Cosmology Seminar DATE: 06-05-2009 TIME: 12:00 noon (Wed) PLACE: Physics building (#54) room 207 TITLE: Newtonian gravity in the language of spacetime geometry: a large step in the direction of general relativity SPEAKER: Avi Rabinowitz, NYU, USA ABSTRACT/COMMENTS: A heuristic approach appropriate for physics students familiar with Newtonian physics, the divergence and gradient, and elementary special relativity. The lecture can also be considered as a heuristic introduction to some basic aspects of general relativity. From gideonc at bgu.ac.il Sun May 3 12:03:01 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Sun May 3 12:03:02 2009 Subject: [Phys-seminars] 2009-05-07 Physics Colloquium Message-ID: <200905030903.MAA11429081@tzin.bgu.ac.il> Physics Colloquium DATE: 07-05-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Adaptive response by state-dependent inactivation SPEAKER: Prof. Naama Brenner, Department of Chemical Engineering, Technion ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_B/brenner.html Refreshments are served at 3:20pm From ibar at bgu.ac.il Wed May 6 09:03:11 2009 From: ibar at bgu.ac.il (ilana) Date: Wed May 6 09:03:18 2009 Subject: [Phys-seminars] 2009-05-12 Lasers Seminar Message-ID: <20090506060314.4B75C146CA7@smtp2.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 12-05-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Imaging methods of cold atoms SPEAKER: Mr. David Moravchik, Department of Physics, Ben Gurion University of the Negev, Beer Sheva ABSTRACT/COMMENTS: Cold atoms research raises new imaging challenges for different types of experiments. Although it is possible to extract information using conventional destructive imaging techniques based upon absorption or emission, it is impossible to track the time evolution of the same atomic cloud without significantly altering its properties. Thus, it is essential, in some experiments, to use an efficient non-destructive imaging system in order to minimally affect the atoms. I will present different imaging methods such as dark-ground and phase contrast, characterize the differences between them and find the limits of non-destructive imaging methods under non-ideal conditions such as near atomic resonance and using large Fourier filters. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090506/227019c1/attachment.htm From nano at bgu.ac.il Wed May 6 09:35:44 2009 From: nano at bgu.ac.il (Nano) Date: Wed May 6 09:36:11 2009 Subject: [Phys-seminars] 2009-05-06 Reminder Nanotechnology seminar Message-ID: <936CF46D94F3455E87AC3DEE6876D028@estinano> Nanotechnology Seminar, Wednesday 6.5.2009, 12:00 building 29, room 307,Chemistry Department seminar room Insight into the Unusual Self-Assembly of Bioinspired Amphiphiles into Ribbons and Nanotubes Dganit Danino Department of Biotechnology and Food Engineering Technion, Israel Institute of Technology Abstract: The growing field of nanotechnology has historically emphasized the ?bottom-up? approach, in which precursor molecules are able to assemble spontaneously (?self-assemble?) into structures of interest when placed in water or other solvents. This ability to self-assemble is inherent in biomolecules such as proteins, peptides and lipids, as well as in synthetic amphiphiles, i.e., surfactants and detergents. Although self-assembly has had a long history, there are certain types of self-assembled structures that are much less understood than others. One such class of structures comprises 1-dimensional (1-D) typically bilayered aggregates, which encompass twisted and helical ribbons, and nanotubes. These nanostructures could find many analogous applications to CNTs, which include encapsulation and controlled release, sensors for biomolecules, and as templates for construction of metal rods and inorganic (e.g., silica) hollow tubules. Curved ribbons and nanotubes are formed only by certain amphiphilic molecules, not all, and are stable only under a specific set of conditions. They are especially ubiquitous when the amphiphiles have amino-acid or sugar headgroups. In other classes of amphiphiles, flat ribbons and vesicles form. The talk will focus on our recent studies exploring the relations between the molecular structure and the self-assembly mechanism, and the factors driving the formation of these nanostructured liquids. Special emphasize will be given to the application of advanced cryogenic electron microscopy methods in these studies. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090506/bb271c77/attachment-0001.htm From nano at bgu.ac.il Thu May 7 13:00:52 2009 From: nano at bgu.ac.il (Nano) Date: Thu May 7 13:01:18 2009 Subject: [Phys-seminars] 2009-05-13 Nanotechnology seminar-E.Lifshitz Message-ID: <86E718ED7BB841F89A6C624586EC3486@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Efrat Lifshitz 130509.doc Type: application/msword Size: 668672 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090507/d9ba6cdc/EfratLifshitz130509-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Efrat LIfshitz 130509.pdf Type: application/pdf Size: 178666 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090507/d9ba6cdc/EfratLIfshitz130509-0001.pdf From gideonc at bgu.ac.il Fri May 8 17:28:03 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Fri May 8 17:28:04 2009 Subject: [Phys-seminars] 2009-05-14 Physics Colloquium Message-ID: <200905081428.RAA11960495@tzin.bgu.ac.il> Physics Colloquium DATE: 14-05-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: What Lattice Bosons teach us about unconventional Superconductors SPEAKER: Prof. Assa Auerbach, Department of Physics, Technion ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_B/Auerbach.html Refreshments are served at 3:20pm From aaharony at bgu.ac.il Mon May 11 11:04:02 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Mon May 11 11:04:05 2009 Subject: [Phys-seminars] 2009-05-18 Condensed Matter Seminar Message-ID: <200905110804.LAA12209593@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 18-05-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: How `strange metal’ state in high temperature superconductors becomes conventional SPEAKER: Dr. Lia Krusin-Elbaum, IBM T. J. Watson Research Center, Yorktown Heights, New York, USA ABSTRACT/COMMENTS: Unconventional states of metals often emerge from a quantum critical point (QCP) - a zero temperature transition between different ground states of matter. Near QCP the standard Landau\'s Fermi-liquid theory is violated due to quantum fluctuations. Whether the QCP physics can explain the mystery of unusual pseudogapped and `strange metal\' non-Fermi-liquid states of high-Tc superconductors and their connection to the origins of high Tc is a fundamental question still under debate. Experimentally, the putative QCP and its surroundings are masked by superconductivity and remain uncertain. By destroying superconductivity and closing the pseudogap with strong magnetic field in Tl2Ba2CuO6+x, we can map the onsets of both pseudogap (T*) and Fermi liquid (TFL) states using transport measurements in a previously unexplored low-temperature, heavy charge-doping region of the phase diagram. We show that T* and TFL converge in the zero-temperature limit at a unique value of doping which shifts with field concurrently with the suppression of Tc. The effect of magnetic field is the key. In a field, the pseudogap boundary T* has scaling properties, and it develops a thermodynamic divergence in the quantum limit corresponding to a zero entropy jump. We conclude that quantum criticality, `strange’ metal states and superconductivity in cuprates are intimately linked. From aaharony at bgu.ac.il Mon May 11 17:40:16 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Mon May 11 17:40:16 2009 Subject: [Phys-seminars] 2009-05-25 Condensed Matter Seminar Message-ID: <200905111440.RAA12261359@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 25-05-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Semilinear response and RMT for the heating rate of cold atoms in vibrating traps SPEAKER: Alex Stotland, Physics Dept., Ben Gurion University ABSTRACT/COMMENTS: The calculation of the heating rate of cold atoms in vibrating traps requires a theory that goes beyond the Kubo linear response formulation. If a strong \"quantum chaos\" assumption does not hold, the analysis of transitions shows similarities with a percolation problem in energy space. We show how the texture and the sparsity of the perturbation matrix, as determined by the geometry of the system, dictate the result. An improved sparse random matrix model is introduced: it captures the essential ingredients of the problem, and leads to a generalized variable range hopping picture. From silon at bgu.ac.il Tue May 12 17:15:13 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Tue May 12 17:15:13 2009 Subject: [Phys-seminars] 2009-05-20 Particles and Fields Seminar Message-ID: <200905121415.RAA12373854@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 20-05-2009 TIME: 12:00 (Wed) PLACE: Physics building (#54) room 207 TITLE: Dark matter search: on Earth, from the Sun, and from Galaxy SPEAKER: Wai-Yee, Physics Department, University of Illinois at Chicago, ABSTRACT/COMMENTS: We analyze the discovery potential of various dark matter scenarios from Supersymmetry, Extra Dimensions, or Little Higgs models in the spin dependent cross section measurements. Our results are used to predict the high energy neutrino flux from the dark matter annihilation in the solar core to be detected by ICECUBE experiment. Recent physics implications of the cosmic ray experiments are discussed. From silon at bgu.ac.il Tue May 12 17:15:23 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Tue May 12 17:15:22 2009 Subject: [Phys-seminars] 2009-05-20 Astrophysics and Cosmology Seminar Message-ID: <200905121415.RAA12340791@tzin.bgu.ac.il> Astrophysics and Cosmology Seminar DATE: 20-05-2009 TIME: 12:00 noon (Wed) PLACE: Physics building (#54) room 207 TITLE: Dark matter search: on Earth, from the Sun, and from Galaxy SPEAKER: Wai-Yee, Physics Department, University of Illinois at Chicago, ABSTRACT/COMMENTS: We analyze the discovery potential of various dark matter scenarios from Supersymmetry, Extra Dimensions, or Little Higgs models in the spin dependent cross section measurements. Our results are used to predict the high energy neutrino flux from the dark matter annihilation in the solar core to be detected by ICECUBE experiment. Recent physics implications of the cosmic ray experiments are discussed. From ibar at bgu.ac.il Tue May 12 17:21:57 2009 From: ibar at bgu.ac.il (ilana) Date: Tue May 12 17:22:03 2009 Subject: [Phys-seminars] 2009-05-19 Lasers Seminar Message-ID: <20090512142159.1B7D5146BE8@smtp2.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 19-05-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Electrons, self-assembled DNA, and Photons - What can we learn by combining them? SPEAKER: Prof. Ron Naaman, Department of Chemical Physics, Weizmann Institute of Science ABSTRACT/COMMENTS: Many of the mutagenic or lethal effects of ionization radiation can be attributed to damage caused to the DNA by low-energy electrons. To gain insight on the parameters affecting this process, we used laser-based methods and measured the low-energy electron transmission yield through self-assembled monolayers of short DNA oligomers. The electrons that are not transmitted are captured by the layer. Using two-photon processes we verified where on the DNA the electrons are residing. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090512/0cca2268/attachment.htm From nano at bgu.ac.il Wed May 13 09:32:57 2009 From: nano at bgu.ac.il (Nano) Date: Wed May 13 09:33:25 2009 Subject: [Phys-seminars] 2009-05-13 Reminder Nanotechnology seminar-E.Lifshitz Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Efrat Lifshitz 130509.doc Type: application/msword Size: 668672 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090513/ba890a52/EfratLifshitz130509-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Efrat LIfshitz 130509.pdf Type: application/pdf Size: 178666 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090513/ba890a52/EfratLIfshitz130509-0001.pdf From nano at bgu.ac.il Wed May 13 12:06:58 2009 From: nano at bgu.ac.il (Nano) Date: Wed May 13 12:07:24 2009 Subject: [Phys-seminars] 2009-05-20 Nanotechnology seminar-Yossi Rosenwaks Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... 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Name: Yossi Rosenwaks 200509.pdf Type: application/pdf Size: 39232 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090513/aa830d12/YossiRosenwaks200509-0001.pdf From physics at bgu.ac.il Thu May 14 12:39:03 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Thu May 14 12:39:04 2009 Subject: [Phys-seminars] 2009-05-20 Particles and Fields Seminar Message-ID: <200905140939.MAA12515967@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 20-05-2009 TIME: 10:00am (Wed) PLACE: Physics building (#54) room 207 TITLE: Black Hole Entropy: Towards New (Inner) Horizons SPEAKER: Finn Larsen, Unversity of Michigan, Department of Physics USA and CERN Geneva, Switzerland ABSTRACT/COMMENTS: The thermodynamic entropy of a black hole is essentially the area of its horizon, expressed as function of physical parameters such as mass, angular momentum, and charges. The talk reviews the formula in the context of string theory, a setting that provides a striking structure to the entropy that is not widely known. The result has a geometrical interpretation that gives a significant role to the inner horizon of the black hole. We discuss the prospects for a microscopic theory of all black holes, including conventional Schwarzchild and Kerr solutions. From gideonc at bgu.ac.il Thu May 14 18:49:30 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Thu May 14 18:49:29 2009 Subject: [Phys-seminars] 2009-05-21 Physics Colloquium Message-ID: <200905141549.SAA12538623@tzin.bgu.ac.il> Physics Colloquium DATE: 21-05-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Baron von Munchaausen and the cat: Swimming in a curved space SPEAKER: Prof. Joseph E. (Yosi) Avron, Department of Physics, Technion ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_B/Avron.html Refreshments are served at 3:20pm From ibar at bgu.ac.il Tue May 19 16:44:40 2009 From: ibar at bgu.ac.il (ilana) Date: Tue May 19 16:44:53 2009 Subject: [Phys-seminars] 2009-05-26 Lasers Seminar Message-ID: <20090519134448.13B45146CD2@smtp1.bgu.ac.il> Please notice the special hour ANNOUNCEMENT==> Lasers Seminar DATE: 26-05-2009 TIME: 4:00pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Bose-Einstein Condensates on the AtomChip SPEAKER: Mr. Ran Salem, Department of Physics, Ben Gurion University of the Negev ABSTRACT/COMMENTS: The AtomChip is a unique tool for studying atom surface interactions and one dimensional Bose-Einstein Condensates (BEC). Ultracold atoms are trapped a few micrometers from a room-temperature surface in magnetic traps produced by running currents through micro-fabricated wires on the chip. In this talk, I will present recent results from the AtomChip experiment at BGU, in which a cold atomic cloud or BEC is trapped using the AtomChip wires. In brief, I will describe our work in which the cold atoms were used to study directional deviation of the current density in micro-fabricated wires. I will also describe an on-going experiment using a wire designed to generate a periodic magnetic trapping potential. Such a trap offers interesting possibilities for measuring quantum coherence and dephasing of separated condensates in a one dimensional trap. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090519/3991528c/attachment.htm From nano at bgu.ac.il Wed May 20 10:00:13 2009 From: nano at bgu.ac.il (Nano) Date: Wed May 20 10:00:43 2009 Subject: [Phys-seminars] 2009-05-20 Reminder-Nanotechnology seminar-Yossi Rosenwaks Message-ID: <7D89942F4C5142DAB77EB7B8FC50EF4B@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Yossi Rosenwaks 200509.doc Type: application/msword Size: 29184 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090520/dde21b1e/YossiRosenwaks200509-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Yossi Rosenwaks 200509.pdf Type: application/pdf Size: 39232 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090520/dde21b1e/YossiRosenwaks200509-0001.pdf From aaharony at bgu.ac.il Wed May 20 10:22:04 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Wed May 20 10:22:03 2009 Subject: [Phys-seminars] 2009-06-01 Condensed Matter Seminar Message-ID: <200905200722.KAA13099081@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 01-06-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: NO SEMINAR TODAY - see the conference on \"Perspectives of Mesoscopic Physics\", celebrating the 70th birthday of Joe Imry, at the WIS (Sunday and Monday from 10 am) SPEAKER: , ABSTRACT/COMMENTS: From physics at bgu.ac.il Sun May 24 10:46:59 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Sun May 24 10:47:00 2009 Subject: [Phys-seminars] 2009-06-08 Special Seminar Message-ID: <200905240746.KAA13465802@tzin.bgu.ac.il> Special Seminar DATE: 08-06-2009 TIME: 13:30pm (Mon) PLACE: Physics Building 54 Room 207 TITLE: Liquid-Gas phase transition in heavy ION collisions SPEAKER: Prof. Shalom Shlomo, Cyclotron Institute, Texas A&M University College Station USA ABSTRACT/COMMENTS: In an intermediate energy heavy ion collision a dense and hot nuclear System is created which then fragmented. Assuming a thermal and chemical equilibrium at freeze out, the temperature T of the disassembling hot system is then determined from the ratios of the yields of the emitted fragments using the method first introduced by Saha. The dependence of excitation energy on T, i.e, the caloric curve, was found to show irregularities which may be interpreted as a possible signal for liquid gas phase transition. In the analysis of the experimental data of fragment yields we have considered the effects of: (i) the Coulomb interaction, (ii) post emission decay (iii) flow due to compression and of (iv) the medium on the binding energies of clusters. From aaharony at bgu.ac.il Mon May 25 11:30:45 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Mon May 25 11:30:45 2009 Subject: [Phys-seminars] 2009-06-08 Condensed Matter Seminar Message-ID: <200905250830.LAA13549661@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 08-06-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Luttinger Liquids out of Equilibrium SPEAKER: Prof. Yuval Gefen, Weizmann Institute, Rehovot ABSTRACT/COMMENTS: For more than 40 years Luttinger liquids have been a paradigm for studying electronic (particularly strongly interacting) systems. in one dimension. Often one reorts to (operator) bosonization, within which the low lying excitations of these models are described in terms of an effective bosonic field. I will argue that once dealing with one-dimensional systems out of equilibrium, standard operator bosonization breaks down. I will explain how one can address that kind of physics, and describe the calculation of tunneling density-of-states anomalies and energy relaxation out of equilibrium. From aaharony at bgu.ac.il Mon May 25 12:39:58 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Mon May 25 12:39:58 2009 Subject: [Phys-seminars] 2009-06-15 Condensed Matter Seminar Message-ID: <200905250939.MAA13575650@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 15-06-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Quantum decay into a non-flat continuum SPEAKER: Itamar Sela, Ben Gurion University ABSTRACT/COMMENTS: We study the decay of a prepared state into non-flat continuum. We find that the survival probability $P(t)$ might exhibit either stretched-exponential or power-law decay, depending on non-universal features of the model. Still there is a universal characteristic time $t_0$ that does not depend on the functional form. It is only for a flat continuum that we get a robust exponential decay that is insensitive to the nature of the intra-continuum couplings. The analysis highlights the co-existence of perturbative and non-perturbative features in the local density of states, and the non-linear dependence of $1/t_0$ on the strength of the coupling. From ibar at bgu.ac.il Tue May 26 17:46:06 2009 From: ibar at bgu.ac.il (ilana) Date: Tue May 26 17:46:22 2009 Subject: [Phys-seminars] 2009-06-02 Lasers Seminar Message-ID: <20090526144618.557A5146C65@smtp1.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 02-06-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Polymerization and phase transition kinetics in polydiacetylene SPEAKER: Ms. Olga Shusterman, Department of Physics, Ben Gurion University of the Negev, ABSTRACT/COMMENTS: Polymerization of polydiacetylene (PDA) is done usually by UV light -- monomers become a blue phase which then become a red phase, and finally degradates. We show that visible light can also polymerize and that the process is a two-photon one. We monitor the process by a Raman laser at 633 nm with variable intensity I and show that the Raman cross section at short times increases as I^3 , corresponding to a two-photon process. The UV generated blue and red phases of PDA are monitored by their optical absorption. Fits to various reaction kinetic models suggests that there is a reversible intermediate phase between the blue and red ones. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090526/09893c83/attachment.htm From nano at bgu.ac.il Wed May 27 10:02:38 2009 From: nano at bgu.ac.il (Nano) Date: Wed May 27 10:03:14 2009 Subject: [Phys-seminars] 2009-03-03 Nanotechnology seminar-Jacob Klein Message-ID: <75752E7C317C4FCAB04E6C5A7E060130@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Jacob Klein 030609.doc Type: application/msword Size: 28160 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090527/8ed6d0df/JacobKlein030609-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Jacob Klein 030609.pdf Type: application/pdf Size: 33638 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090527/8ed6d0df/JacobKlein030609-0001.pdf From nano at bgu.ac.il Wed May 27 10:07:19 2009 From: nano at bgu.ac.il (Nano) Date: Wed May 27 10:07:53 2009 Subject: [Phys-seminars] 2009-06-03 Nanotechnology seminar-Jacob Klein Message-ID: <88EB51818BF74D8F8D15A4915B468F96@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Jacob Klein 030609.doc Type: application/msword Size: 28160 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090527/c08ec352/JacobKlein030609-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Jacob Klein 030609.pdf Type: application/pdf Size: 33638 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090527/c08ec352/JacobKlein030609-0001.pdf From gideonc at bgu.ac.il Thu May 28 14:19:50 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Thu May 28 14:19:54 2009 Subject: [Phys-seminars] 2009-06-04 Physics Colloquium Message-ID: <200905281119.OAA13877897@tzin.bgu.ac.il> Physics Colloquium DATE: 04-06-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Spin reversal in molecular nanomagnets: tunneling and magnetic avalanches SPEAKER: Prof. Myriam Sarachik, CUNY, New York ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_B/Sarachik.html Refreshments are served at 3:20pm From silon at bgu.ac.il Mon Jun 1 14:38:52 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Mon Jun 1 14:38:54 2009 Subject: [Phys-seminars] 2009-06-08 Particles and Fields Seminar Message-ID: <200906011138.OAA14261504@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 08-06-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Holographic techniques for condensed matter systems SPEAKER: Christopher Herzog , Princeton University, New Jersey, USA ABSTRACT/COMMENTS: Gauge/gravity duality, a concept which emerged from string theory holds promise for revealing the secrets of certain strongly interacting real world condensed matter systems. Historically, string theorists presented their subject as a promising framework for a quantum theory of gravity. More recently, the AdS/CFT correspondence and gauge/gravity dualities have emerged as powerful tools for using what we already know about gravity to investigate the properties of strongly interacting field theories. In this talk, I will survey recent developments where black holes are used to calculate the thermodynamic and transport properties of quantum critical systems, superconductors, superfluids, and fermions at unitarity. From ibar at bgu.ac.il Tue Jun 2 17:22:47 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Jun 2 17:23:13 2009 Subject: [Phys-seminars] 2009-06-09 Lasers Seminar Message-ID: <20090602142307.8D4FD146CCC@smtp2.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 09-06-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Ultrasound modulated light tomography: A new modality for functional imaging of tissues SPEAKER: Dr. Bruno Sfez, Electro-Optics Division, NRC Soreq, Yavne, ABSTRACT/COMMENTS: Light as a diagnosis tool to probe biological tissues is very attractive, because it gives access to their molecular composition. Light as an imaging tool is even more exciting since it gives access to functional mapping. However imaging tissues with light is quite a formidable task because tissues strongly diffuse light. Although for more than 20 years different techniques have been developed, most of them based on inverse-scattering algorithms, the challenge has remained. The technique developed in our laboratory is based on the combination of light and ultrasound where light is used for probing the molecules and the ultrasound for providing the mapping. The advantage of this technique is that 3 dimensional data can be obtained, instead of 2 dimensional ones, which greatly facilitates reconstruction algorithms. More precisely, laser light is coupled into the biological tissue (or turbid medium phantom) and is strongly diffused. Outside the medium, a speckle image is formed, whose details strongly depends on the exact photons trajectories inside the medium. When an ultrasound wave is focused at a particular point in the medium, it slightly modifies the local index and the position of the scatterers harmonically. The speckle intensity is therefore modulated at the ultrasound frequency. The amplitude of the optical signal at the ultrasound frequency is directly related to the amount of photons that crossed the ultrasound focus. An image can be built by scanning the ultrasound focus within the medium. From this image, it is possible to retrieve the photons flux within the medium as well as the local absorption or scattering. We have demonstrated for the first time 3D high resolution optical imaging in living mice (resolution: 2 mm, imaging depth: 2 cm) in vivo as well as a series of pre-clinical trials in order to evaluate the use of this technique for the detection and monitoring of osteoporosis. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090602/9ded4d1d/attachment.htm From nano at bgu.ac.il Wed Jun 3 09:33:15 2009 From: nano at bgu.ac.il (Nano) Date: Wed Jun 3 09:33:54 2009 Subject: [Phys-seminars] 2009-06-03 Reminder-Nanotechnology seminar-Jacob Klein Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Jacob Klein 030609.doc Type: application/msword Size: 28160 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090603/986612b0/JacobKlein030609-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Jacob Klein 030609.pdf Type: application/pdf Size: 33641 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090603/986612b0/JacobKlein030609-0001.pdf From nano at bgu.ac.il Thu Jun 4 10:52:05 2009 From: nano at bgu.ac.il (Nano) Date: Thu Jun 4 10:52:45 2009 Subject: [Phys-seminars] 2009-06-10 Nanotechnology seminar-Itay Rousso Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... 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Name: Itay Rousso 100609.pdf Type: application/pdf Size: 23457 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090604/0c9bc7ba/ItayRousso100609-0001.pdf From gideonc at bgu.ac.il Thu Jun 4 17:55:18 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Thu Jun 4 17:55:18 2009 Subject: [Phys-seminars] 2009-06-11 Physics Colloquium Message-ID: <200906041455.RAA14507816@tzin.bgu.ac.il> Physics Colloquium DATE: 11-06-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Quasicrystals - Some of nature\'s most intriguing forms of matter SPEAKER: Prof. Ron Lifshitz, Raymond and Beverly Sackler School of Physics & Astronomy, Tel Aviv University ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_B/Lifshitz.html Refreshments are served at 3:20pm From aaharony at bgu.ac.il Mon Jun 8 19:20:49 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Mon Jun 8 19:20:49 2009 Subject: [Phys-seminars] 2009-06-22 Condensed Matter Seminar Message-ID: <200906081620.TAA14864574@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 22-06-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: On The Nature of the Superconductor-Insulator Transition in Disordered Systems SPEAKER: Amir Erez, Physics Department, Ben Gurion University ABSTRACT/COMMENTS: We examine the superconductor-insulator transition (SIT) within the framework of the disordered Negative U Hubbard Model, beyond the mean-field approximation. Using a classical Monte Carlo method, we calculate the effects of temperature and disorder on global phase coherence. We present some numerical results and discuss their implications regarding the SIT. From nano at bgu.ac.il Tue Jun 9 10:16:56 2009 From: nano at bgu.ac.il (Nano) Date: Tue Jun 9 10:17:37 2009 Subject: [Phys-seminars] 2009-06-24 IKI-institute Day Message-ID: <460C8877A3D543DFB4AE8E163062DB4B@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: program IKI day-v2-general.pdf Type: application/pdf Size: 50716 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090609/6ac9d181/programIKIday-v2-general-0001.pdf From physics at bgu.ac.il Tue Jun 9 11:57:05 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Jun 9 11:57:06 2009 Subject: [Phys-seminars] 2009-06-10 Nanotechnology Workshop Message-ID: <200906090857.LAA14903413@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 10-06-2009 TIME: 12:00 (noon) PLACE: Chemistry club (Building #29, room 307) TITLE: The role of the tectorial membrane in the mechanics of hearing SPEAKER: Itay Rousso, Weitzmann Institute ABSTRACT/COMMENTS: From ibar at bgu.ac.il Tue Jun 9 17:26:37 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Jun 9 17:26:42 2009 Subject: [Phys-seminars] 2009-06-16 Lasers Seminar Message-ID: <20090609142637.B2BC8146CA4@smtp2.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 16-06-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Nonlinear Photonic Quasicrystals SPEAKER: Prof. Ron Lifshitz, Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, ABSTRACT/COMMENTS: There is growing interest in the ability to generate quasicrystals, with structure on a mesoscopic scale, ranging from artificially constructed metamaterials such as photonic quasicrystals [1], to self-assembled soft-matter quasicrystals [2,3]. In addition to having promising applications, especially in the optical domain, these materials give us the opportunity to study quasicrystals in ways that were impossible before. I will discuss my work on the design of nonlinear photonic quasicrystals for applications in nonlinear optical frequency conversion [4], as well as the use of nonlinear photonic metamaterials for studying defect dynamics and phason strain relaxation in a quasicrystal [5]. If time permits I will contrast this human-made nonlinear photonic system, whose dynamics are believed to be governed by the so-called nonlinear Schroedinger equation, with self-assembled soft quasicrystals, whose dynamics are believed to be governed by a relaxation of an effective free energy, possibly similar in form to the one we suggested in the past in the context of Faraday Waves [6]. [1] M.E. Zoorob et al., Nature 404 (2000) 740. [2] X. Zeng et al., Nature 428 (2004) 157. [3] K. Hayashida et al., Phys. Rev. Lett. 68 (2007) 195502. [4] R. Lifshitz et al., PRL 95 (2005) 133901; A. Bahabad et al., JOSA B 24 (2007) 1916; and Phil. Mag. 88 (2008) 2285. [5] B. Freedman et al., Nature 440 (2006) 1166; and Nature Materials 6 (2007) 776. [6] R. Lifshitz and D.M. Petrich, PRL 79 (1997) 1261. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090609/25fe7161/attachment.htm From nano at bgu.ac.il Wed Jun 10 09:10:45 2009 From: nano at bgu.ac.il (Nano) Date: Wed Jun 10 09:11:27 2009 Subject: [Phys-seminars] 2009-06-10 Reminder-Nanotechnology seminar-Itay Rousso Message-ID: <6B86493D86494E6EA421C6F80ED2D864@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Itay Rousso 100609.doc Type: application/msword Size: 27648 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090610/6e14b84c/ItayRousso100609-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Itay Rousso 100609.pdf Type: application/pdf Size: 23463 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090610/6e14b84c/ItayRousso100609-0001.pdf From silon at bgu.ac.il Wed Jun 10 18:13:42 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Wed Jun 10 18:13:43 2009 Subject: [Phys-seminars] 2009-06-15 Particles and Fields Seminar Message-ID: <200906101513.SAA15013422@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 15-06-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Localized Structures in Conformal Gravity SPEAKER: Yosef Verbin, The Open University, Raanana, lsrael ABSTRACT/COMMENTS: From nano at bgu.ac.il Thu Jun 11 12:56:17 2009 From: nano at bgu.ac.il (Nano) Date: Thu Jun 11 12:57:00 2009 Subject: [Phys-seminars] 2009-06-17 Nanotechnology seminar-Oded Millo Message-ID: <417C8212B2884BB78B992CF454B43082@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Oded Millo 170609.pdf Type: application/pdf Size: 36830 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090611/0009ca60/OdedMillo170609-0001.pdf -------------- next part -------------- A non-text attachment was scrubbed... Name: Oded Millo 170609.doc Type: application/msword Size: 28672 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090611/0009ca60/OdedMillo170609-0001.doc From gideonc at bgu.ac.il Thu Jun 11 18:15:31 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Thu Jun 11 18:15:33 2009 Subject: [Phys-seminars] 2009-06-18 Physics Colloquium Message-ID: <200906111515.SAA15067431@tzin.bgu.ac.il> Physics Colloquium DATE: 18-06-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: DNA and chromatin dynamics studied by single molecule methods and computer modeling SPEAKER: Prof. Dr. Jorg Langowski, University of Heidelberg ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_B/Jorg.html Refreshments are served at 3:20pm From nano at bgu.ac.il Sun Jun 14 14:28:04 2009 From: nano at bgu.ac.il (Nano) Date: Sun Jun 14 14:28:47 2009 Subject: [Phys-seminars] 2009-06-15 Departmental Seminar-Prof. Ira A. Weinstock-Dept of Chemistry, BGU Message-ID: <682BBFC8E97E4AE4BF6C3852F65D2AE2@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Ira Weinstock_June 15_2009.doc Type: application/msword Size: 30208 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090614/12f0c1bf/IraWeinstock_June15_2009-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Ira Weinstock_June 15_2009.pdf Type: application/pdf Size: 23315 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090614/12f0c1bf/IraWeinstock_June15_2009-0001.pdf From silon at bgu.ac.il Mon Jun 15 15:54:22 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Mon Jun 15 15:54:22 2009 Subject: [Phys-seminars] 2009-06-22 Particles and Fields Seminar Message-ID: <200906151254.PAA15410976@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 22-06-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: LATTICE GAUGE THEORY BEYOND THE STANDARD MODEL SPEAKER: Benjamin Svetitsky , Physics Department, Tel Aviv University, Tel Aviv, Israel ABSTRACT/COMMENTS: From nano at bgu.ac.il Tue Jun 16 16:00:59 2009 From: nano at bgu.ac.il (Nano) Date: Tue Jun 16 16:01:45 2009 Subject: [Phys-seminars] 2009-06-17 Reminder: Nanotechnology seminar-Oded Millo Message-ID: <31F6C4AC522946679A4E0217A3D29D57@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Oded Millo 170609.pdf Type: application/pdf Size: 36830 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090616/ea02014d/OdedMillo170609-0001.pdf -------------- next part -------------- A non-text attachment was scrubbed... Name: Oded Millo 170609.doc Type: application/msword Size: 28672 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090616/ea02014d/OdedMillo170609-0001.doc From ibar at bgu.ac.il Tue Jun 16 17:42:34 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Jun 16 17:42:43 2009 Subject: [Phys-seminars] 2009-06-23 Lasers Seminar Message-ID: <20090616144238.C2DBF146CEE@smtp1.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 23-06-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Melting Curve Measurement in Diamond Anvil Cell above 400 K by IR Pyrometry SPEAKER: Dr. Aviva Melchior, Physics Department, Nuclear Research Center ? Negev, P.O.B. 9001, Beer-Sheva, Israel ABSTRACT/COMMENTS: Studying the melting curve of a physical system requires controlling of both pressure and temperature. The main static pressure tool today is the diamond anvil cell (DAC), operative from a few kilobars to a few megabars. Melting curve measurements in a DAC are carried out by laser heating combined with pyrometry, and are usually limited to temperatures above 1000 K using optics and detectors in the visible range. We have built a pyrometer in the IR and expanded the lower limit of temperature detection to 400 K. The pyrometer is designed for very low thermal radiation intensities, measured sequentially through a set of bandpass filters in the range of 1.2 - 3.4 mm using very efficient IR photodetectors. The melting curve of Zinc was measured up to 25 GPa. The results are in very good agreement with previous results that were taken up to 6 GPa in a large volume press. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090616/aed02899/attachment.htm From nano at bgu.ac.il Sun Jun 21 10:30:09 2009 From: nano at bgu.ac.il (Nano) Date: Sun Jun 21 10:30:57 2009 Subject: [Phys-seminars] 2009-06-24 Reminder: IKI instiyute day Message-ID: <55301B7DABDC41DAAA3926EBB35A4A52@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: IKI day-Posters and presenters list _final_.pdf Type: application/pdf Size: 98407 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090621/c922be6c/IKIday-Postersandpresenterslist_final_-0001.pdf -------------- next part -------------- A non-text attachment was scrubbed... Name: program IKI day-v2-general.pdf Type: application/pdf Size: 50716 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090621/c922be6c/programIKIday-v2-general-0001.pdf From nano at bgu.ac.il Sun Jun 21 14:04:49 2009 From: nano at bgu.ac.il (Nano) Date: Sun Jun 21 14:05:40 2009 Subject: [Phys-seminars] 2009-06-29 Nanotechnology seminar-Niels Gronbech Jensen- Notice the change in day Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Niels Gronbech Jensen 290609.doc Type: application/msword Size: 28160 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090621/79721bed/NielsGronbechJensen290609-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Niels Gronbech Jensen 290609.pdf Type: application/pdf Size: 23831 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090621/79721bed/NielsGronbechJensen290609-0001.pdf From aaharony at bgu.ac.il Mon Jun 22 11:18:19 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Mon Jun 22 11:18:20 2009 Subject: [Phys-seminars] 2009-06-29 Condensed Matter Seminar Message-ID: <200906220818.LAA5218964@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 29-06-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Conformal restriction in condensed matter physics SPEAKER: Dr. Eldad Bettelheim, Racah Institute, Hebrew University, Jerusalem ABSTRACT/COMMENTS: Conformal restriction theory allows one to describe two dimensional models at criticality which possess conformal symmetry and have vanishing central charge. The theory, developed by probabilists, describes completely the geometry of certain clusters in such systems. I will discuss in particular how the theory can be applied to the integer quantum Hall transition making use of the Chalker-Conddington model. From ibar at bgu.ac.il Tue Jun 23 17:16:53 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Jun 23 17:17:00 2009 Subject: [Phys-seminars] 2009-06-30 Lasers Seminar Message-ID: <20090623141652.A31DC146C6E@smtp2.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 30-06-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: The semiclassical route to quantum dynamics in real time SPEAKER: Prof. Eli Pollak, Chemical Physics Department, Weizmann Institute of Science, Rehovot ABSTRACT One of the central challenges facing theoretical Chemistry and Physics is the computation of quantum dynamics in complex systems. Due to the oscillatory nature of quantum mechanical properties, this problem has remained elusive even with present state of the art powerful computational facilities. The need for a general methodology cannot be overstated, since the ability of computing quantum dynamics in real time would impact our understanding of diverse topics, such as spectroscopy, molecular reaction dynamics, solid state physics, ab-initio quantum chemistry, quantum computation, Bose-Einstein condensates to name a few. In this talk I will discuss the semiclassical initial value representation approach, comparing it to the classical Wigner dynamics approximation. Using a novel time dependent perturbation theory, I will show that the semiclassical approximation to the exact quantum propagator may be considered to be the zero-th order term in a time dependent perturbation theory expansion of the exact propagator. This leads to profound new insight into quantum dynamics. Exact quantum dynamics may be obtained purely from classical paths. Deep tunneling is effected through coherent classical paths. New and efficient approximate semiclassical propagators may be used to improve convergence properties. Examples of applications will include vibrational relaxation and the general semiclassical theory for dissipative systems. A first example of ab-initio semiclassical dynamics will be presented for the absorption spectrum of formaldehyde. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090623/b9574857/attachment.htm From silon at bgu.ac.il Thu Jun 25 16:19:53 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Thu Jun 25 16:19:54 2009 Subject: [Phys-seminars] 2009-07-06 Particles and Fields Seminar Message-ID: <200906251319.QAA14299970@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 06-07-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Gravitational Dirac bubbles SPEAKER: Mr. Shimon Rubin, BGU, Physics Dep. ABSTRACT/COMMENTS: A gravitational extension of Dirac\'s \"Extensible model of the > electron\"is presented. > The Dirac bubble, treated as a 3-dim electrically charged brane, > is dynamically > embedded within a 4-dim Z_{2}-symmetric Reissner-Nordstrom bulk. > Crucial to our analysis is the gravitational extension of > Dirac\'s brane variation > prescription; its major effect is to induce a novel > geometrically originated > contribution to the energy-momentum tensor on the brane. > In turn, the effective potential which governs the evolution of > the bubble > exhibits a global minimum, such that the radius of the bubble > stays finite > even at the limit where the mass of the configuration tends to zero. > This way, without giving up the positivity of the bubble\'s > surface tension, > one avoids the so-called \'classical radius of the electron problem\'. > Stability with respect to small deformations in the bubble\'s > shape (no longer spherical) > is manifest. > From nano at bgu.ac.il Mon Jun 29 09:01:21 2009 From: nano at bgu.ac.il (Nano) Date: Mon Jun 29 09:02:15 2009 Subject: [Phys-seminars] 2009-06-29 Reminder: Nanotechnology seminar-Niels Gronbech Jensen Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... 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Name: Niels Gronbech Jensen 290609.pdf Type: application/pdf Size: 23831 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090629/531469fe/NielsGronbechJensen290609-0001.pdf From gideonc at bgu.ac.il Mon Jun 29 11:50:34 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Mon Jun 29 11:50:35 2009 Subject: [Phys-seminars] 2009-07-02 Physics Colloquium Message-ID: <200906290850.LAA16613045@tzin.bgu.ac.il> Physics Colloquium DATE: 02-07-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Adaptive response by state-dependent inactivation SPEAKER: Prof. Naama Brenner, Department of Chemical Engineering, Technion ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_B/brenner.html Refreshments are served at 3:20pm From aaharony at bgu.ac.il Tue Jun 30 09:34:42 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Tue Jun 30 09:34:44 2009 Subject: [Phys-seminars] 2009-07-06 Condensed Matter Seminar Message-ID: <200906300634.JAA6844256@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 06-07-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Possible evidence for magnetic order at the interface between SrTiO3 and LaAlO3 from transport measurements SPEAKER: Dr. Yoram Dagan, School of Physics and Astronomy Tel Aviv University ABSTRACT/COMMENTS: Interfaces between strongly correlated electron materials can be very different from their constituents. It has been shown that if LaAlO¬3 is epitaxially grown on TiO2 terminated SrTiO3 a two dimensional electron gas is formed at the interface between these insulators. This interface was later shown to be superconducting and magnetic. We deposit a few monolayers of LaAlO¬3 on SrTiO3. Our samples are atomically flat, single crystals as seen in RHEED, AFM and TEM. >From our data we were able to find evidence for magnetic ordering below 35K. The strong anisotropy of the magnetoresistance is indicative of a novel transport mechanism. We conjecture that an antiferromagnetic state existing below a Neel temperature of 35K may explain both the magnetic and superconducting properties of this interface. In addition we can find an upper limit for the width of the electron confinement using high magnetic field transport measurements. We also were able to identify the structural phase transition occurring in the bulk substrate at 105 K using transport measurements. The transition temperature near the surface is reduced possibly due to strain effects. From nano at bgu.ac.il Wed Jul 1 13:44:34 2009 From: nano at bgu.ac.il (Nano) Date: Wed Jul 1 13:45:32 2009 Subject: [Phys-seminars] 2009-07-08 Nanotechnology seminar - Gregory B. McKenna Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Gregory B. McKenna 080709.doc Type: application/msword Size: 588288 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090701/ea02b1a1/GregoryB.McKenna080709-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Gregory B. McKenna 080709.pdf Type: application/pdf Size: 174524 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090701/ea02b1a1/GregoryB.McKenna080709-0001.pdf From ibar at bgu.ac.il Thu Jul 2 15:05:39 2009 From: ibar at bgu.ac.il (ilana) Date: Thu Jul 2 15:05:54 2009 Subject: [Phys-seminars] 2009-07-07 Lasers Seminar Message-ID: <20090702120540.C83FC146CE8@smtp2.bgu.ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 07-07-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Detection of biochip arrays by Raman spectroscopy SPEAKER: Mrs. Keren Kantarovich, Department of Physics, Ben Gurion University of the Negev, Beer Sheva ABSTRACT/COMMENTS: Biochip-arrays constitute a rapidly increasing research field driven by the versatility of sensing devices and the importance of their applications in the bioanalytical field, drug development, environmental, food analysis, etc. Common strategies used for creating biochips and for reading them have extensive limitations, motivating development of miniature biochips and label-free formats for identification of biochemical activities. To achieve these goals we combined the nano fountain pen (NFP) method for printing microscale features with Raman and surface enhanced Raman spectroscopy (SERS) for reading droplets of synthetic receptors. These receptors include molecular imprinted polymers (MIPs), which are prepared by polymerization of suitable functional and cross-linking monomers around molecular templates. They are characterized by higher physical and chemical stability than biomacromolecules and therefore are potentially very suitable as recognition elements for biosensors, or biochips. The monitored bands in the Raman and SERS spectra could be related to the taken up compound, allowing direct detection of the template, i.e., the b-blocking drug propranolol, in the imprinted droplets. The NFP deposition combined with Raman and SERS open the possibility of using this approach for monitoring MIP-based sensors on micro-scale. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090702/6e62449e/attachment.htm From gideonc at bgu.ac.il Fri Jul 3 20:26:24 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Fri Jul 3 20:26:25 2009 Subject: [Phys-seminars] 2009-07-09 Physics Colloquium Message-ID: <200907031726.UAA14222858@tzin.bgu.ac.il> Physics Colloquium DATE: 09-07-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Lights, Camera, Action SPEAKER: Dr. Yael Roichman, Department of Chemistry, Tel Aviv University ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_B/Roichman.html Refreshments are served at 3:20pm From nano at bgu.ac.il Sun Jul 5 11:03:50 2009 From: nano at bgu.ac.il (Nano) Date: Sun Jul 5 11:04:48 2009 Subject: [Phys-seminars] 2009-07-12 Nanotechnology Special seminar- Jennifer Ohayon Message-ID: <7FFCE81F51A245CABB5D16E6DB8609CF@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Jeniffer Ohayon-Speical Seminar 120709.doc Type: application/msword Size: 28160 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090705/e3cded82/JenifferOhayon-SpeicalSeminar120709-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Jeniffer Ohayon-Speical Seminar 120709.pdf Type: application/pdf Size: 27197 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090705/e3cded82/JenifferOhayon-SpeicalSeminar120709-0001.pdf From aaharony at bgu.ac.il Tue Jul 7 11:33:49 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Tue Jul 7 11:33:52 2009 Subject: [Phys-seminars] 2009-07-13 Condensed Matter Seminar Message-ID: <200907070833.LAA17272500@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 13-07-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Tb3+ in TbCo3B2, a singlet ground state system, studied by inelastic neutron scattering SPEAKER: Oleg Ribin, Ben Gurion University ABSTRACT/COMMENTS: The results of inelastic neutron scattering by the hexagonal TbCo3B2 and Tb0.75Y0.25Co3B2, at several temperatures are reported. The scheme of the crystal field levels of Tb3+ at the paramagnetic phase is determined. This scheme contains a non-magnetic singlet (Gamma1) as a ground state. Inelastic neutron scattering at low temperature (10 K), leads to a different energy level scheme, where the singlet ground state is ferromagnetic with \\ne 0. This is a \"self induced\" ferromagnetism on the Tb sub-lattice, resulting from admixture of higher crystal field levels into the singlet ground state, by the exchange field. The resulting magnitudes of these ground state magnetic moments are 5.6(3) and 3(1) muB for TbCo3B2 and Tb0.75Y0.25Co3B2, respectively. These values are much smaller than the free ion value of 9 muB and are in agreement with previously observed values. Such large reductions are characteristic of the \"self induced\" ferromagnetism. Temperature dependence of the magnetic moment, magnetic anisotropy, Tb sub-lattice dilution and magnetic susceptibility are discussed. From physics at bgu.ac.il Tue Jul 7 14:33:20 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Tue Jul 7 14:33:23 2009 Subject: [Phys-seminars] 2009-07-08 Nanotechnology Workshop Message-ID: <200907071133.OAA17273867@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 08-07-2009 TIME: 16:00 pm (Wed) PLACE: Chemistry club (Building #29, room 307) TITLE: \"Flux Correlation Approach to Electronic Transport through Molecular Junctions\" SPEAKER: Maytal Caspary Toroker & Uri Peskin, The Schulich Faculty of Chemistry and Lise Meitner Center for Computational Quantum Chemistry Technion, Haifa ABSTRACT/COMMENTS: From ibar at bgu.ac.il Tue Jul 7 16:50:06 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Jul 7 16:50:25 2009 Subject: [Phys-seminars] 2009-07-14 Lasers Seminar Message-ID: <20090707135020.D78FC146CB4@smtp1.bgu.ac.il> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... 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Name: not available Type: image/gif Size: 876 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090707/8ced5e9e/attachment-0001.gif -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/octet-stream Size: 1604 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090707/8ced5e9e/attachment.obj From nano at bgu.ac.il Wed Jul 8 10:08:05 2009 From: nano at bgu.ac.il (Nano) Date: Wed Jul 8 10:09:07 2009 Subject: [Phys-seminars] 2009-07-08 Reminder: Nanotechnology seminar - Gregory B. McKenna Message-ID: <6CECD3A76E3D40268D7C565803040351@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Gregory B. McKenna 080709.doc Type: application/msword Size: 588288 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090708/4843ed60/GregoryB.McKenna080709-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Gregory B. McKenna 080709.pdf Type: application/pdf Size: 174524 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090708/4843ed60/GregoryB.McKenna080709-0001.pdf From nano at bgu.ac.il Sun Jul 12 10:31:37 2009 From: nano at bgu.ac.il (Nano) Date: Sun Jul 12 10:32:41 2009 Subject: [Phys-seminars] 2009-07-12 Reminder-Nanotechnology Special seminar- Jennifer Ohayon Message-ID: <143E004C53474A50A3D1B511284BA9A1@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Jeniffer Ohayon-Speical Seminar 120709.doc Type: application/msword Size: 28160 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090712/9d35fbce/JenifferOhayon-SpeicalSeminar120709-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Jeniffer Ohayon-Speical Seminar 120709.pdf Type: application/pdf Size: 27197 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090712/9d35fbce/JenifferOhayon-SpeicalSeminar120709-0001.pdf From nano at bgu.ac.il Sun Jul 12 16:16:07 2009 From: nano at bgu.ac.il (Nano) Date: Sun Jul 12 16:17:12 2009 Subject: [Phys-seminars] 2009-07-15 Nanotechnology Seminar-Antoine Kahn Message-ID: <13F3AD0203EC4D24930149C0DAFF63AF@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Antoine Kahn 150709.doc Type: application/msword Size: 29184 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090712/25be9877/AntoineKahn150709-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Antoine Kahn 150709.pdf Type: application/pdf Size: 27728 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090712/25be9877/AntoineKahn150709-0001.pdf From gideonc at bgu.ac.il Sun Jul 12 16:25:54 2009 From: gideonc at bgu.ac.il (gideonc@bgu.ac.il) Date: Sun Jul 12 16:25:54 2009 Subject: [Phys-seminars] 2009-07-16 Physics Colloquium Message-ID: <200907121325.QAA16724797@tzin.bgu.ac.il> Physics Colloquium DATE: 16-07-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Towards molecular modulation of electronic devices. New and renewed vistas for solar cells? SPEAKER: Prof. David Cahen, Department of Chemistry, Weizmann Institute ABSTRACT/COMMENTS: For abstract please enter the link below: http://physweb.bgu.ac.il/EVENTS/COLLOQ/collq09_B/Cahen.html Refreshments are served at 3:20pm From nano at bgu.ac.il Wed Jul 15 09:13:55 2009 From: nano at bgu.ac.il (Nano) Date: Wed Jul 15 09:15:01 2009 Subject: [Phys-seminars] 2009-07-15 Reminder: Nanotechnology seminar - Antoine Kahn Message-ID: <575FEF165EB74F018FC79D7D79292D81@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Antoine Kahn 150709.doc Type: application/msword Size: 29184 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090715/38324a42/AntoineKahn150709-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Antoine Kahn 150709.pdf Type: application/pdf Size: 27728 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090715/38324a42/AntoineKahn150709-0001.pdf From silon at bgu.ac.il Fri Jul 24 15:56:50 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Fri Jul 24 15:56:51 2009 Subject: [Phys-seminars] 2009-07-30 HEP Seminar - on Thursday! Message-ID: <200907241256.PAA18807499@tzin.bgu.ac.il> HEP Seminar - on Thursday! DATE: 30-07-2009 TIME: 14:00pm (Thursday) PLACE: Physics building (#54) room 207 TITLE: Roaming among free fermion models SPEAKER: Alon Farragi , Liverpool University ABSTRACT/COMMENTS: From ibar at bgu.ac.il Mon Aug 10 10:01:35 2009 From: ibar at bgu.ac.il (ilana) Date: Mon Aug 10 10:01:40 2009 Subject: [Phys-seminars] 2009-08-17 Lasers Seminar Message-ID: <0EE187934E494D079AD4213FCAFE0BAE@IlanaPC> ANNOUNCEMENT==> Special Lasers Seminar DATE: 17-08-2009 TIME: 10:00am (Mon) PLACE: Physics building (#54) room 207 TITLE: Optimization of supersonic chemical oxygen-iodine laser SPEAKER: Mr. Arje Katz, Department of Physics and Mechanical Engineering, Ben Gurion University of the Negev ABSTRACT/COMMENTS: A detailed parametric study of a supersonic chemical oxygen-iodine laser (COIL) will be presented. The first aim of the study has been reaching the maximum possible chemical efficiency in a 5-cm gain-length device and enabling further improvement of the efficiency by extending the length of the gain region to 10 cm. A record-breaking value (~ 40%) for the chemical efficiency in a supersonic 5-cm gain-length COIL was achieved and followed by the achievement of 35% efficiency and > 0.6 kW power in a 10-cm gain-length COIL. The second aim has been the study of power and gain enhancement in a supersonic COIL by electrically dissociating I2 prior to its mixing with O2(1?) and thus reducing the loss of O2(1?). The method is based on applying corona/glow electrical discharge in the transonic section of the secondary flow in the COIL supersonic nozzle. Pre-dissociation of 1.7% I2 by the discharge resulting in 70% power enhancement at rather high I2/O2 ratio, 1.6% was achieved, close to the optimal value (~ 2.5%) for operation of COILs with supersonic mixing. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20090810/d22e19f8/attachment.htm From silon at bgu.ac.il Tue Sep 1 01:06:10 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Tue Sep 1 01:06:18 2009 Subject: [Phys-seminars] 2009-09-14 Particles and Fields Seminar Message-ID: <200908312206.BAA901841@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 14-09-2009 TIME: 10:00am (Mon) PLACE: Physics building (#54) room 207 TITLE: Constraining the Dark Energy\'s Equation of state using Three dimensional Weak Gravitational Lensing SPEAKER: Daniel Levy, BGU ABSTRACT/COMMENTS: From silon at bgu.ac.il Wed Sep 2 16:39:57 2009 From: silon at bgu.ac.il (silon@bgu.ac.il) Date: Wed Sep 2 16:39:58 2009 Subject: [Phys-seminars] 2009-09-16 Astrophysics and Cosmology Seminar Message-ID: <200909021339.QAA1037451@tzin.bgu.ac.il> Astrophysics and Cosmology Seminar DATE: 16-09-2009 TIME: 12:00 noon (Wed) PLACE: Physics building (#54) room 207 TITLE: Anomalous Resistivity-Enabled Disk Formation in Magnetized Cloud Cores SPEAKER: Ruben Krasnopolsky , Academia Sinica ABSTRACT/COMMENTS: Accretion disks are needed by most jet launching mechanisms. However, disk formation in star-forming cloud cores is hindered by excessive magnetic braking. Previous work indicates that braking torques can suppress the formation of rotationally supported disks, both in the ideal MHD limit and in the presence of ambipolar diffusion (for the expected magnetization levels and typical rates of cosmic ray ionization). Our recent simulations show that Ohmic dissipation can in principle enable disk formation. We follow for 30,000 years the collapse of a rotating, magnetized envelope onto a central mass, using a range of values of resistivity. For the smaller resistivities in the range, magnetic braking still prevents disk formation. A Keplerian disk appears for eta of the order of 10^19 cm^2/s, an anomalous resistivity much larger than the classical microscopic value. We explore the dependence of this resistivity value on core magnetization. From ibar at bgu.ac.il Tue Oct 13 11:30:52 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Oct 13 11:31:01 2009 Subject: [Phys-seminars] 2009-10-20 Lasers Seminar Message-ID: <001901ca4be7$dbc6d510$93547f30$@ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 20-10-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Optical Properties of Group IV-monoxides under Pressure SPEAKER: Mr. Asaf Pesach, Department of Physics, Ben Gurion University of the Negev, ABSTRACT/COMMENTS: Application of very high pressure significantly alters the nature of intermolecular interaction, chemical bonding, molecular configuration, and crystal structure of solids. Finger prints of pressure-induced changes in the charge carriers mobility and structural phase transition in group IV elements monoxides were monitored using state of the art IR spectroscopy equipment with high pressure facility and Raman scattering. While the divalence of the chalcogenides in these compounds, gives rise to the commonly electronic configuration of lone pairs, we have found diversity in the pressure dependent evolution of both structural and electrical properties of these compounds. The optical properties of these compounds under pressure represent symmetry distortions and Mott transition (SnO and PbO) on one hand, and Anderson transition (SiO) on the other hand. In the latter case, a model Hamiltonian for bipolaron to extended states crossover under high pressure is studied. Vibrational spectroscopy observations were supported by pressure dependent electrical measurements and x-ray diffraction. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091013/5f16f50e/attachment.htm From nano at bgu.ac.il Wed Oct 14 15:12:23 2009 From: nano at bgu.ac.il (Nano) Date: Wed Oct 14 15:14:17 2009 Subject: [Phys-seminars] 2009-10-21 Nanotechnology Seminar-Michael Bendikov Message-ID: <948AFAF68D4846F8ACCEDB954365E12A@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Michael Bendikov 211009.doc Type: application/msword Size: 818688 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091014/aefddb19/MichaelBendikov211009-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Michael Bendikov 211009.pdf Type: application/pdf Size: 98134 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091014/aefddb19/MichaelBendikov211009-0001.pdf From manassen at bgu.ac.il Mon Oct 19 11:11:01 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Mon Oct 19 11:10:52 2009 Subject: [Phys-seminars] 2009-10-19 Condensed Matter Seminar Message-ID: <200910190911.LAA4890215@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 19-10-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Interaction between the magnetic and superconducting order parameters in a LSCO wire studied via muon spin rotation SPEAKER: Meni Shay, Technion ABSTRACT/COMMENTS: In this talk, recent results about the coupling between the magnetic and superconducting order parameters in LSCO will be presented. This coupling is investigated in an 8 m long meander wire made of a La1.94Sr0.06CuO4 film having a cross section of 0.5um times 100um. The magnetic order parameter is determined using the Low-Energy muon spin relaxation technique. The superconducting order parameter is characterized by transport measurements and modified by high current density. We find that, when the superconducting order parameter is suppressed by the current, the magnetic transition temperature, Tm, increases. The extracted sign and magnitude of the Ginzburg-Landau coupling constant indicate that the two orders are repulsive, and that the LSCO system is located close to the border between first and second order phase transition. From ymeir at bgu.ac.il Mon Oct 19 16:51:04 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Mon Oct 19 16:50:56 2009 Subject: [Phys-seminars] 2009-10-22 Physics Colloquium Message-ID: <200910191451.QAA4919589@tzin.bgu.ac.il> Physics Colloquium DATE: 22-10-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Exploration of the Kuiper Belt SPEAKER: Re\'em Sari, Racach Institute, Hebrew University ABSTRACT/COMMENTS: The Kuiper Belt is a collection of icy objects at the outskirts of our solar system, just external to the orbit of Neptune. They are believed to be pristine objects left over from the epoch of planet formation. We review processes in planet formation and discuss how they are reflected in today\'s Kuiper Belt. We show first results from a new survey to detect small, sub-kilometer objects, and compare the findings with theories of collisional cascades. Refreshments will be served at 15:20 From ibar at bgu.ac.il Tue Oct 20 22:00:03 2009 From: ibar at bgu.ac.il (Ilana Bar) Date: Tue Oct 20 22:00:10 2009 Subject: [Phys-seminars] 2009-10-27 Lasers Seminar Message-ID: ANNOUNCEMENT==> Lasers Seminar DATE: 27-10-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Organic Photovoltaic Cells: Current Status and Possible Ways to Improve their Efficiency SPEAKER: Dr. Rafi Shikler, Department of Electrical and Computer Engineering, Ben Gurion University f the Negev ABSTRACT/COMMENTS: In this talk I will discuss the relatively new topic of organic solar cells. I will introduce the concept of photovoltaic cells in inorganic semiconductor. This will be followed by a review of organic solar cell with emphasize on the differences between the two. I will describe the current status of commercial organic solar cells that already reach efficiency of ~6%. We will then divide the process of light to electricity conversion into steps and see what can be done in order to improve the efficiency of organic cells. I will especially focus on schemes that will enhance the absorption in these structures. Prof. I. Bar Department of Physics Ben-Gurion University of the Negev Beer Sheva 84105 ISRAEL? -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091020/12f72041/attachment.htm From manassen at bgu.ac.il Wed Oct 21 09:24:58 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Wed Oct 21 09:25:05 2009 Subject: [Phys-seminars] 2009-10-26 Condensed Matter Seminar Message-ID: <200910210724.JAA77518@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 26-10-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Insights into single molecule dynamics SPEAKER: Golan Bel, Center for Nonlinear Studies and CCS-3, Los Alamos National Laboratory ABSTRACT/COMMENTS: Recent advances in technology have enabled studying the dynamics of single molecules. What new insights can be revealed by these experiments which cannot be seen in bulk measurements? In this talk I will focus on two examples where we showed that studying single molecules reveals new phenomena. The first is the case of anomalous diffusion in an equilibrium environment. The continuous time random walk with a power-law distribution of sojourn times is a common model to describe subdiffusion processes. A particle which undergoes such a process will visit all sites of a finite system, yet the process is non-ergodic. We clarify the concept of weak ergodicity breaking and calculate the distribution of occupation times from which the time averages of physical observables can be derived. Unlike in ergodic systems even at the infinite long time limit, the occupation times (and therefore the physical observables) are random quantities [1]. I will also discuss another model for anomalous diffusion due to coupling between stochastic processes which can lead to ergodic or non-ergodic behavior for different coupling functions [2]. In both models the single molecule properties provide an insight into the dynamical mechanism, which could not be obtained from ensemble measurements. The second example I will discuss is a non-equilibrium system, a single molecule excited by a monochromatic laser field. I will introduce an extension of the generating function technique for the calculation of photon emission statistics for systems governed by multi-level quantum dynamics. This extension enables studying the statistics of photons that are emitted from specific transitions and subject to quantum coherence. Several model calculations illustrate the generality of the technique and highlight quantitative and qualitative differences between quantum mechanical models and related stochastic approximations. I will also introduce the moment-generating function for photon emissions in which the frequencies of the fluoresced photons are explicitly considered. Calculations were performed for the case of a two-level dye molecule, showing that measured photon statistics will display a strong and nonintuitive dependence on detector bandwidth. It will also be demonstrated that the anti-bunching phenomenon, associated with negative values of Mandel’s Q parameter, results from correlations between photons with well separated frequencies [3]. These two examples show that single molecule measurements can provide new information about the observed system both in equilibrium and non-equilibrium conditions. Moreover, new phenomena which are observed only at the single molecule level can favor certain microscopic models over others. [1] G. Bel and E. Barkai, PRL 94, 240602 (2005);PRE 73, 016125 (2006);EPL 74, 15 (2006). [2] G. Bel and I. Nemenman, New J. of Phys. 11, 083009 (2009). [3] G. Bel and F. Brown, J. Phys. Chem. B 110, 19066 (2006);PRL 102, 018303 (2009). From ymeir at bgu.ac.il Wed Oct 21 11:37:25 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Wed Oct 21 11:37:26 2009 Subject: [Phys-seminars] 2009-10-29 Physics Colloquium Message-ID: <200910210937.LAA89865@tzin.bgu.ac.il> Physics Colloquium DATE: 29-10-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: CP violation goes to Stockholm SPEAKER: Yossi Nir, Department of Particle Physics and Astrophysics, Weizmann Institute ABSTRACT/COMMENTS: The laws of Nature are different for matter and antimatter. In the last ten years there has been a huge progress in our understanding of this phenomenon, known as \"CP violation\". I will explain the Kobayashi-Maskawa theory of CP violation, and the way in which the experiments known as \"B-factories\" have proven that the theory is correct. Refreshments are served at 3:20pm From physics at bgu.ac.il Thu Oct 22 14:04:25 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Thu Oct 22 14:04:26 2009 Subject: [Phys-seminars] 2009-11-04 Astrophysics and Cosmology Seminar Message-ID: <200910221204.OAA185938@tzin.bgu.ac.il> Astrophysics and Cosmology Seminar DATE: 04-11-2009 TIME: 12:00 noon (Wed) PLACE: Physics building (#54) room 207 TITLE: Nonlinear waves in relativistic two-fluid hydrodynamics SPEAKER: Mr. Lev Haim, ABSTRACT/COMMENTS: Studies of nonlinear waves in relativistic plasmas are important in connection with collisionless shocks which are expected to form in a number of astrophysical objects dominated by relativistic plasmas. We study stationary one-dimensional nonlinear waves propagating in the direction perpendicular to the external magnetic field, within the two-fluid approach. From ibar at bgu.ac.il Tue Oct 27 17:11:19 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Oct 27 17:11:48 2009 Subject: [Phys-seminars] 2009-11-03 Lasers Seminar Message-ID: <004a01ca5717$bcce9540$366bbfc0$@ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 03-11-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Raman study of low doped manganites SPEAKER: Mr. Evgeny Shabaev, Physics Department, Ben Gurion University of the Negev, Beer Sheva ABSTRACT/COMMENTS: Low doped La1-xCaxMnO3 manganites with x = 0.18 and x = 0.2 are characterized by great variety of structural, electronic and magnetic phases. These were studied using Raman spectroscopy method. Four of the structural phases are identified. Three critical points separate these phases, namely, (O*, O* + O', O', and O*) and obtained experimentally. Also, the Curie temperature Tc was measured for the two compounds. The results were analyzed taking into consideration strong interplay between Raman modes as were observed in our experiment. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091027/98b92bcf/attachment.htm From ymeir at bgu.ac.il Wed Oct 28 07:09:17 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Wed Oct 28 07:09:22 2009 Subject: [Phys-seminars] 2009-11-05 Physics Colloquium Message-ID: <200910280509.HAA734915@tzin.bgu.ac.il> Physics Colloquium DATE: 05-11-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Approach to equilibrium of a Quantum Glass SPEAKER: Zvi Ovadyahu, Racah Institute of Physics, the Hebrew University, Jerusalem ABSTRACT/COMMENTS: The out-of-equilibrium transport properties of some Anderson insulators exhibit slow relaxation and memory effects that are common characteristics of glasses. However, the temperature dependence of the relaxation in these electronic glasses differs from most other glasses. The possible relevance of the Quantum Zeno Effect and Quantum Friction to the Electron-Glass dynamics will be discussed. Z. O. Phys. Rev. Lett., 99, 226603 (2007); Phys. Rev. B 78, 195120 (2008); Phys. Rev. Lett., 102, 206601 (2009). Refreshments are served at 3:20pm From manassen at bgu.ac.il Wed Oct 28 12:56:33 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Wed Oct 28 12:56:37 2009 Subject: [Phys-seminars] 2009-11-02 Condensed Matter Seminar Message-ID: <200910281056.MAA02945@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 02-11-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Title: Geometric phase interferometry with cold atoms SPEAKER: Omri Gat, Racah Institute, Hebrew University ABSTRACT/COMMENTS: Abstract: A cold atom wave packet prepared with a narrow momentum distribution in a weakly forced two-dimensional optical lattice undergoes Bloch oscillations, remaining localized in both position and momentum, and accumulates a dynamical phase and the Berry-Wilkinson geometric phase associated with its orbit in the Brillouin zone. This phase can be observed by letting the wave packet impinge on a cold atom beam splitter. The reflected wave packet follows a Brillouin zone orbit parallel to that of the transmitted wave packet, and after one period the transmitted and reflected wave packets intersect the beam splitter and recombine. An interferometric analysis then allows to measure the geometric phase, and map the Berry curvature of the band. From physics at bgu.ac.il Wed Oct 28 14:35:03 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Wed Oct 28 14:35:06 2009 Subject: [Phys-seminars] 2009-10-28 Physical Chemistry Seminar Message-ID: <200910281235.OAA11316@tzin.bgu.ac.il> Physical Chemistry Seminar DATE: 28-10-2009 TIME: 4:00pm (Wed) PLACE: Chemistry club (Building #29, room 306) TITLE: BEC SPEAKER: , Ptof. Yehuda Band ABSTRACT/COMMENTS: From danrich at bgu.ac.il Mon Nov 2 14:10:36 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Mon Nov 2 14:10:38 2009 Subject: [Phys-seminars] 2009-11-04 Nanotechnology Workshop Message-ID: <200911021210.OAA300647@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 04-11-2009 TIME: 12:00 (noon) PLACE: Chemistry Dept. Seminar Room (Building #29, room 306) TITLE: \"Cooperative bidirectional motion of motor proteins\" by B. Gur and \"Cathodoluminescence study of ZnxCd1-xSe/C Core/Shell Nanocrystals with phase-separation\" by Y. Estrin SPEAKER: Barak Gur and Yevgeni Estrin, Dept. of Physics, Ben-Gurion University These seminars are being presented in partial fulfillment of the M.Sc. degree in Physics. Each student will speak for 30 minutes. ABSTRACT/COMMENTS: B. Gur: A two state ratchet model is used to study the cooperative bidirectional motion of molecular motors on cytoskeletal tracks with randomly alternating polarities. Our model is based on a previous proposed model [Badual et al., Proc. Natl. Acad. Sci. U.S.A. 99, 6696 (2002)] for collective motor dynamics and, in addition, takes into account the cooperativity effect arising from the elastic tension that develops in the cytoskeletal track due to the joint action of the walking motors. We show that this additional cooperativity effect leads to a dramatic reduction in the characteristic reversal time of the bidirectional motion, especially in systems with a large number of motors. Our model succeeds in explaining recent experimental results which have been in contrast to previous theoretical predictions. Y. Estrin: The optical properties and carrier relaxation kinetics of ZnxCd1-xSe/C core/shell nanocrystals with compositional phase separation occurring on a ~1-5 nm size scale were examined with time-resolved cathodoluminescence (CL) spectroscopy and CL monochromatic imaging. The CL spectral lineshape was found to depend on the level of excitation, temperature, and the time-window during time-delayed spectroscopy. The kinetics of carrier thermalization and transfer between Cd-rich phase-separated regions and the homogenous ZnCdSe alloy were examined. We show that the rare phenomenon of compositional phase separation in II-VI nanocrystals leads to interesting and potentially useful optical properties. From ibar at bgu.ac.il Wed Nov 4 08:56:30 2009 From: ibar at bgu.ac.il (ilana) Date: Wed Nov 4 08:57:03 2009 Subject: [Phys-seminars] 2009-11-10 Lasers Seminar Message-ID: <006701ca5d1b$f0327820$d0976860$@ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 10-11-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Shedding Light on Biomolecules: Raman Spectral Signatures as Dynamical and Conformational Probes SPEAKER: Mr. Amir Golan, Department of Physics, Ben Gurion University of the Negev, Beer-Sheva ABSTRACT/COMMENTS: The dynamics and structure of biomolecules play an important role in determining their selectivity and functionality and therefore attract considerable interest. A first experimental demonstration, employing a method of vibrational spectroscopy, i.e., ion loss stimulated Raman spectroscopy (ILSRS), will be presented. It will be shown that by coupling ILSRS with vibrationally mediated photodissociation the mode selectivity in the C-H stretch region of methylamine could be quantified. In addition, obtaining the vibrational signatures via ILSRS and comparing them with quantum mechanical calculation results revealed a unique powerful means for investigating and mapping the conformation of gas phase phenylethylamine molecules. The results show the great potential of the ILSRS technique, for obtaining the spectral signatures of biomolecules, while using available laser sources. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091104/036929c9/attachment.htm From physics at bgu.ac.il Wed Nov 4 09:21:31 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Wed Nov 4 09:21:34 2009 Subject: [Phys-seminars] 2009-11-25 Astrophysics and Cosmology Seminar Message-ID: <200911040721.JAA469760@tzin.bgu.ac.il> Astrophysics and Cosmology Seminar DATE: 25-11-2009 TIME: 12:00 noon (Wed) PLACE: Physics building (#54) room 207 TITLE: Observations, theory and implications of thermal emission from gamma-ray bursts SPEAKER: Dr. Asaf Pe\'er, Space Telescope Science Institute ABSTRACT/COMMENTS: Recent analysis show evidence for a thermal emission component that accompanies the non-thermal emission during the prompt phase of gamma- ray bursts (GRBs). First, I will show the evidence for the existence of this component; Second, I will show that this component is naturally explained by considering emission from the photosphere, taking into account high latitude emission from optically thick relativistically expanding plasma. I will show that the thermal flux is expected to decay at late times as F_BB ~ t^{-2}, and the observed temperature as T ~ t^{-\\alpha}, with \\alpha ~ 1/2 - 2/3. These theoretical predictions are in very good agreement with the observations. Finally, I will discuss three implications of this interpretation: (a) The relation between thermal emission and high energy, non-thermal spectra observed by FERMI. (b) I will show how thermal emission can be used to directly measure the Lorentz factor of the flow and the initial radius of the jet. (c) I will show how lack of detection of thermal component can be used to constrain the composition of GRB jets. From nano at bgu.ac.il Wed Nov 4 12:24:24 2009 From: nano at bgu.ac.il (Nano) Date: Wed Nov 4 12:26:31 2009 Subject: [Phys-seminars] 2009-11-11 Nnaotechnology seminar- Alexandra Navrotsky Message-ID: <2BD388E44599414497B05284D21D0287@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Alexandra Navrotsky 111109.doc Type: application/msword Size: 143872 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091104/8ec86710/AlexandraNavrotsky111109-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Alexandra Navrotsky 111109.pdf Type: application/pdf Size: 96159 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091104/8ec86710/AlexandraNavrotsky111109-0001.pdf From danrich at bgu.ac.il Wed Nov 4 14:33:21 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Wed Nov 4 14:33:26 2009 Subject: [Phys-seminars] 2009-11-11 Nanotechnology Workshop Message-ID: <200911041233.OAA487976@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 11-11-2009 TIME: 12:00 (noon) PLACE: Chemistry Dept. Seminar Room (Building #29, room 307) TITLE: Calorimetric Studies of the Energetics of Nanomaterials and their Surfaces and Interfaces SPEAKER: Alexandra Navrotsky, Peter A Rock Thermochemistry Laboratory and NEAT ORU University of California at Davis ABSTRACT/COMMENTS: Calorimetric studies of nanomaterials, using oxide melt solution calorimetry and water vapor adsorption calorimetry, have produced a wealth of data on the energetics of phase transformation and the surface energies of hydrated and dehydrated surfaces of nanoparticulate oxides. Competition between surface energy and phase transformation energy lead to crossovers in phase stability at the nanoscale. The surface energies of polymorphs metastable in the bulk are smaller than those of the stable polymorph and decrease with increasing metastability, regardless of the sign of the density difference. Wet surfaces have smaller surface energies than dry ones. Oxyhydroxides have smaller surface energies than oxides. In ZnO, for which nanoparticles of different morphologies can be prepared, surface energy increases in the order nanoparticles, nanorods, nanoneedles, reflecting the predominance of different surface planes. Very recently, the interfacial energy of a dense nanoceramic sampl e of yttria stabilized zirconia (YSZ) has been measured. These results and systematic trends provide benchmarks for theoretical calculations. From idobd at bgu.ac.il Thu Nov 5 09:48:29 2009 From: idobd at bgu.ac.il (idobd@bgu.ac.il) Date: Thu Nov 5 09:48:32 2009 Subject: [Phys-seminars] 2009-11-09 Particles and Fields Seminar Message-ID: <200911050748.JAA564136@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 09-11-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: sQGP from holography SPEAKER: , Michael Lublinsky BGU ABSTRACT/COMMENTS: I will give a brief review on applications of string/gravity methods to strongly coupled gauge plasmas. This field of research has emerged from experiments at the RHIC, which creates strongly coupled quark gluon plasma.in relativistic collisions of heavy ions. From manassen at bgu.ac.il Thu Nov 5 09:54:46 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Thu Nov 5 09:54:48 2009 Subject: [Phys-seminars] 2009-11-09 Condensed Matter Seminar Message-ID: <200911050754.JAA561441@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 09-11-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Counting statistics in multiple path geometries and quantum stirring SPEAKER: Prof. Doron Cohen, Dept. of Physics, Ben Gurion University ABSTRACT/COMMENTS: The amount Q of particles that are transported via a path of motion is characterized by its expectation value and by its variance Var(Q). We analyze what happens if a particle has two optional paths available to get from one site to another site, and in particular what is Var(Q) for the current which is induced in a quantum stirring device. A novel interference effect shows up in the counting statistics calculation for subsequent multiple path Landau-Zener crossings. [1] J. Phys. A 41, 075302 (2008) [2] Phys. Rev. A 77, 012109 (2008) [3] http://physics.bgu.ac.il/~dcohen/ARCHIVE From ymeir at bgu.ac.il Sun Nov 8 11:11:41 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Sun Nov 8 11:11:42 2009 Subject: [Phys-seminars] 2009-11-10 Physics Colloquium Message-ID: <200911080911.LAA840477@tzin.bgu.ac.il> Physics Colloquium DATE: 10-11-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Low temperature universality in disordered solids SPEAKER: Moshe Schechter, Physics Department, Ben Gurion University ABSTRACT/COMMENTS: Amorphous solids, polymers, and disordered solids show striking universal characteristics at low temperatures, despite enormous differences in their microscopic structure. Discovered 40 years ago, this universality has emerged as one of the outstanding unsolved questions in condensed matter physics. The phenomenological model of tunneling two level systems (TLS) (Anderson, Helperin, and Varma, and Philips) accounts well for much of the observed phenomena. However, the model can not account for the smallness and universality of the phonon attenuation nor for the energy scale (3K) below which universality is observed, and the nature of the TLS is not known. Here we show that two kinds of TLS exist, differing by their symmetry under inversion. The symmetric TLS interact weakly with the phonon field, but gap the strongly interacting TLS below 3K, and therefore dictate weak and universal phonon attenuation at low temperatures. Refreshments are served at 3:20pm From ymeir at bgu.ac.il Sun Nov 8 11:15:51 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Sun Nov 8 11:15:52 2009 Subject: [Phys-seminars] 2009-11-12 Physics Colloquium - correction Message-ID: <200911080915.LAA843204@tzin.bgu.ac.il> Physics Colloquium - correction DATE: 12-11-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Low temperature universality in disordered solids SPEAKER: Moshe Schechter, Physics Department, Ben Gurion University ABSTRACT/COMMENTS: Amorphous solids, polymers, and disordered solids show striking universal characteristics at low temperatures, despite enormous differences in their microscopic structure. Discovered 40 years ago, this universality has emerged as one of the outstanding unsolved questions in condensed matter physics. The phenomenological model of tunneling two level systems (TLS) (Anderson, Helperin, and Varma, and Philips) accounts well for much of the observed phenomena. However, the model can not account for the smallness and universality of the phonon attenuation nor for the energy scale (3K) below which universality is observed, and the nature of the TLS is not known. Here we show that two kinds of TLS exist, differing by their symmetry under inversion. The symmetric TLS interact weakly with the phonon field, but gap the strongly interacting TLS below 3K, and therefore dictate weak and universal phonon attenuation at low temperatures. Refreshments are served at 3:20pm From dcohen at bgu.ac.il Sun Nov 8 12:26:00 2009 From: dcohen at bgu.ac.il (Cohen Doron) Date: Sun Nov 8 12:26:03 2009 Subject: [Phys-seminars] 2009-11-09 Condensed Matter Seminar / updated abstract Message-ID: Please note updated abstract -- second part will be about quantum stirring and the many body Landau-Zener transition in BEC. ---- Condensed Matter Seminar ? DATE: 09-11-2009 ? TIME: 11:30am (Mon) ? PLACE: Physics building (#54) room 207 TITLE: Counting statistics in multiple path geometries and quantum stirring SPEAKER: Prof. Doron Cohen, Dept. of Physics, Ben Gurion University ABSTRACT/COMMENTS: The amount Q of particles that are transported via a path of motion is characterized by its expectation value and by its variance Var(Q). We analyze what happens if a particle has two optional paths available to get from one site to another site, and in particular what is Var(Q) for? the current which is induced in a quantum stirring device. A novel interference effect shows up in the counting statistics calculation for subsequent multiple path Landau-Zener crossings. The second part of the talk concerns quantum stirring, and the occupation statistics in the many body Landau-Zener transition of condensed particles that are described by the Bose Hubbard Hamiltonian. [1] J. Phys. A 41, 075302 (2008). [2] Europhysics Lett. 82, 40006 (2008). [3] Phys. Rev. Lett. 102, 230401 (2009). From danrich at bgu.ac.il Mon Nov 9 15:25:09 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Mon Nov 9 15:25:09 2009 Subject: [Phys-seminars] 2009-11-18 Nanotechnology Workshop Message-ID: <200911091325.PAA960710@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 18-11-2009 TIME: 12:00 (noon) PLACE: Chemistry Dept. Seminar Room (Building #29, room 307) TITLE: Electric transport through a single metallic nanoparticle SPEAKER: Prof. Aviad Frydman, Dept. of Physics, Bar Ilan University ABSTRACT/COMMENTS: We have developed a novel method for measuring the conductance versus gate voltage of a metallic nano-particle while varying the coupling to large electric leads. These systems exhibit periodic conductance- vrs – gate voltage peaks which strongly decrease in amplitude as the dot-lead coupling is increased. At the same time an additional set of periodic peaks appear and become the dominant feature for strong coupling. For specific coupling the conductance peaks shift from one frequency to another as a function of applied voltage bias across the dot. Our results exclude the presence of two distinct physical dots but suggest that the second period is due to electronic surface states that play a larger roll the smaller is the dot. I will discuss these results and suggest that they are inherent for chemically formed quantum dots. From ibar at bgu.ac.il Wed Nov 11 09:00:41 2009 From: ibar at bgu.ac.il (ilana) Date: Wed Nov 11 09:01:22 2009 Subject: [Phys-seminars] 2009-11-17 Lasers Seminar Message-ID: <000c01ca629c$ae60cc40$0b2264c0$@ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 17-11-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Intramolecular Dynamics of Methylamine and Methylamine-d3 SPEAKER: Mr. Tal Weiss, Department of Physics, Ben Gurion University of the Negev, ABSTRACT/COMMENTS: The ability to understand the complicated dynamics in molecular systems is of considerable interest since it opens a door to control of molecular processes. Employing electronic action and Doppler spectroscopies on H and D photofragments released in photodissociation of methylamine (CH3NH2) and methylamine-d3 (CD3NH2); we will demonstrate, how a mechanistic insight on H atom tunneling and photodissociation is obtained. The results are supported by theoretical calculations, based on the probability of H atom tunneling on the excited potential energy surface during N-H bond breaking. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091111/406cdc92/attachment.htm From nano at bgu.ac.il Wed Nov 11 09:11:00 2009 From: nano at bgu.ac.il (Nano) Date: Wed Nov 11 09:13:21 2009 Subject: [Phys-seminars] 2009-11-11Reminder: Nnaotechnology seminar- Alexandra Navrotsky Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Alexandra Navrotsky 111109.doc Type: application/msword Size: 143872 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091111/dc1a2111/AlexandraNavrotsky111109-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Alexandra Navrotsky 111109.pdf Type: application/pdf Size: 96159 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091111/dc1a2111/AlexandraNavrotsky111109-0001.pdf From manassen at bgu.ac.il Wed Nov 11 10:13:32 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Wed Nov 11 10:13:35 2009 Subject: [Phys-seminars] 2009-11-16 Condensed Matter Seminar Message-ID: <200911110813.KAA1111547@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 16-11-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Surface morphology as a probe for local surface elastic parameters SPEAKER: Mr. Eldad Peretz, Dept. of Physics, Ben Gurion University ABSTRACT/COMMENTS: The elastic parameters of the surface affect the morphology of the surface, by driving different kind of phenomena, like: mass transport, surface reconstruction, surface roughening, surface faceting, Surface undulation, etx. These phenomena must be taken in account when building devices / structures in the nanometer scale. Despite its importance, the known values of the surface stress and surface strain comes mainly from computer simulations and calculations. These values represent macroscopic values; they are average values that don’t take into account local changes in the atomic structure of the surface. We demonstrate two different cases in which we extract from the surface morphology the local values of surface strain using simple energetic analysis in one case and the local value of surface stress using point force mode of monoatomic steps in the second case. From nano at bgu.ac.il Wed Nov 11 12:03:24 2009 From: nano at bgu.ac.il (Nano) Date: Wed Nov 11 12:05:40 2009 Subject: [Phys-seminars] 2009-11-18 Nnaotechnology seminar- Aviad Frydman Message-ID: <3F2947E411F840A7ADAC3BB114440E8A@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Aviad Frydman 181109.doc Type: application/msword Size: 143872 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091111/9ce7c21d/AviadFrydman181109-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Aviad Frydman 181109.pdf Type: application/pdf Size: 93311 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091111/9ce7c21d/AviadFrydman181109-0001.pdf From idobd at bgu.ac.il Thu Nov 12 10:20:15 2009 From: idobd at bgu.ac.il (idobd@bgu.ac.il) Date: Thu Nov 12 10:20:18 2009 Subject: [Phys-seminars] 2009-11-16 Particles and Fields Seminar Message-ID: <200911120820.KAA1200311@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 16-11-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Observing Dark Energy SPEAKER: Ofer Lahav, University College London ABSTRACT/COMMENTS: There is growing observational evidence that the Universe is flat and it consists of three main ingredients: Baryons, Dark Matter and Dark Energy, which causes an acceleration of the cosmic expansion. The talk will discuss current observational results for Dark Energy and Neutrino masses,and the plans for new deep imaging surveys, in particular the \"Dark Energy Survey\" and the Euclid satellite. From ymeir at bgu.ac.il Sun Nov 15 00:34:56 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Sun Nov 15 00:34:59 2009 Subject: [Phys-seminars] 2009-11-19 Physics Colloquium Message-ID: <200911142234.AAA1461395@tzin.bgu.ac.il> Physics Colloquium DATE: 19-11-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: The largest microscope ever built to study the smallest space-time distances SPEAKER: Prof. Giora Mikenberg, Weizmann Institute and CERN ABSTRACT/COMMENTS: A general overview of the main unknowns in Particle Physics and Astrophysics is given to introduce the importance of the LHC Collider. The LHC collider will start its operation next week and will be able to provide some of the answers. A report will then be presented on the construction and status of the LHC experiments, followed by the expectations for new results in 2010. Refreshments are served at 3:20pm From ibar at bgu.ac.il Wed Nov 18 08:16:42 2009 From: ibar at bgu.ac.il (ilana) Date: Wed Nov 18 08:17:30 2009 Subject: [Phys-seminars] 2009-11-24 Lasers Seminar Message-ID: <003501ca6816$b2b4e810$181eb830$@ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 24-11-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Control and decoherence: control of an excited state objective: optimization principles for hot electron injection in solar acceptors SPEAKER: Professor Ronnie Koslo?, Institute of Chemistry and Fritz Haber Research Center for Molecular Dynamics, Hebrew University of Jerusalem, Jerusalem ABSTRACT/COMMENTS: Coherent control employing a broad band excitation is applied to a branching reaction in the excited state. In weak ?eld for an isolated molecule a control objective is only frequency dependent. This means that phase control of the pulse cannot improve the objective beyond the best frequency selection. Once the molecule is put in a dissipative environment a new time scale emerges. In this study we demonstrate that the dissipation allows to achieve coherent control of branching ratios in the excited state. The model studied contains a nuclear coordinate and three electronic states: the ground and two coupled diabatic excited states. The in?uence of the environment is modeled by the stochastic surrogate Hamiltonian. The excitation is generated by a Gaussian pulse where the phase control introduced a chirp to the pulse. For su?cient relaxation we ?nd signi?cant control in weak ?eld depending on the chirp rate. The observed control is rationalized by a timing argument caused by a focused wavepacket. The initial non adiabatic crossing is enhanced by the chirp. This is followed by energy relaxation which stabilizes the state by having an energy lower than the crossing point. We use these principles to design an acceptor for solar energy composed from three electronic states. The acceptor dark excited state should have a soft vibrational mode with fast relaxation. The bright state should be rigid with the non-adiabatic crossing point slightly below in resonance with the excitation. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091118/225068ab/attachment.htm From nano at bgu.ac.il Wed Nov 18 09:00:38 2009 From: nano at bgu.ac.il (Nano) Date: Wed Nov 18 09:02:53 2009 Subject: [Phys-seminars] 2009-11-18 Reminder: Nnaotechnology seminar- Aviad Frydman Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... 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Name: Aviad Frydman 181109.pdf Type: application/pdf Size: 93311 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091118/0e5a505a/AviadFrydman181109-0001.pdf From aaharony at bgu.ac.il Wed Nov 18 09:31:09 2009 From: aaharony at bgu.ac.il (aaharony@bgu.ac.il) Date: Wed Nov 18 09:31:12 2009 Subject: [Phys-seminars] 2009-11-23 Condensed Matter Seminar Message-ID: <200911180731.JAA1773628@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 23-11-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Mesoscopic Spin Hall Effect in Ballistic 2D Electron System SPEAKER: Dr. Peter Silvestrov, University of Bochum, Germany ABSTRACT/COMMENTS: Spin-Hall effect in ballistic 2D electron gas with Rashba-type spin-orbit coupling is considered. The net out-of-plane spin polarization across the edge of the conductor is universal, i.e. independent of the form of the boundary potential, and appears in the second order in the spin-orbit interaction. Detailed investigation of the case of hard-wall boundary will be presented, which shows in particular an exact vanishing of evanescent modes contribution. In case of a smooth boundary potential the interplay of semiclassical electron motion and quantum dynamics of spins leads to several distinct features in spin density along the edge that originate from accumulation of turning points from many classical trajectories. The total amount of spin accumulated in each of these features exceeds greatly the net spin across the entire edge. From meirav at bgu.ac.il Wed Nov 18 10:43:23 2009 From: meirav at bgu.ac.il (meirav@bgu.ac.il) Date: Wed Nov 18 10:43:25 2009 Subject: [Phys-seminars] 2009-11-23 Particles and Fields Seminar Message-ID: <200911180843.KAA1771364@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 23-11-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Improved relativistic hydrodynamics from AdS/CFT SPEAKER: Michael Lublinsky , BGU ABSTRACT/COMMENTS: I will present a brief introduction to fluid/gravity correspondence. This field of research has recently emerged from the experimental program at the RHIC, where strongly coupled quark gluon plasma is produced in heavy ion collisions. I will also talk about my research focused on generalizing transport coefficients to momenta-dependent functions. From nano at bgu.ac.il Wed Nov 18 12:33:44 2009 From: nano at bgu.ac.il (Nano) Date: Wed Nov 18 12:35:57 2009 Subject: [Phys-seminars] 2009-11-25 Nnaotechnology seminar- Jeffrey Gordon Message-ID: <088A3E13C3054F8A83C837FE893EA078@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Jeffrey Gordon 251109.doc Type: application/msword Size: 143872 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091118/850b777f/JeffreyGordon251109-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Jeffrey Gordon 251109.pdf Type: application/pdf Size: 97632 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091118/850b777f/JeffreyGordon251109-0001.pdf From ymeir at bgu.ac.il Thu Nov 19 12:24:37 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Thu Nov 19 12:24:38 2009 Subject: [Phys-seminars] 2009-11-26 Physics Colloquium Message-ID: <200911191024.MAA1883522@tzin.bgu.ac.il> Physics Colloquium DATE: 26-11-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Applied string theory SPEAKER: Amos Yarom, Princeton University ABSTRACT/COMMENTS: One of the most interesting tools to come out of string theory goes under the name of `the AdS/CFT correspondence\'. This mathematical tool allows for exact computations in strongly coupled gauge theories and has found applications in heavy ion collisions, fluid dynamics and, most recently, superconductivity and superfluidity. After giving an overview of the correspondence, I will discuss several of its implementations. Refreshments are served at 3:20pm From danrich at bgu.ac.il Thu Nov 19 16:35:22 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Thu Nov 19 16:35:24 2009 Subject: [Phys-seminars] 2009-11-25 Nanotechnology Workshop Message-ID: <200911191435.QAA1892133@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 25-11-2009 TIME: 12:00 (noon) PLACE: Chemistry Dept. Seminar Room (Building #29, room 307) TITLE: New synthetic pathways for inorganic nano-materials by concentrated non-coherent light SPEAKER: Prof. Jeffrey Gordon, Dept. of Solar Energy and Environmental Physics, J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer. ABSTRACT/COMMENTS: The discovery of nano-structures synthesized from inorganic compounds opened a new direction in advanced materials. These closed-cage nano-structures and nano-tubes exhibit physico-chemical properties for a rich spectrum of applications. A central challenge is finding high-yield, practical, affordable methods for synthesizing them - processes that involve high temperatures, strongly non-equilibrium reactor conditions, and often high photonic flux. This presentation will cover the development and demonstration of new, efficient, pragmatic optical methods for the synthesis of inorganic nano-materials, based on ultra-bright non-coherent (non-laser) light from the sun and from new generations of short-arc discharge lamps. Successful case studies will include: cage-like nanostructures of dicesium oxide, fullerene-like and nanotube molybdenum disulfide and tungsten disulfide, nanowires and nanospheres of silicon dioxide generated for the first time from pure quartz, nanorods of pure silicon, and more. Some of these nanostructures even achieved fundamentally minimum sizes predicted by molecular structural theory. From manassen at bgu.ac.il Tue Nov 24 18:28:11 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Tue Nov 24 18:28:13 2009 Subject: [Phys-seminars] 2009-11-30 Condensed Matter Seminar Message-ID: <200911241628.SAA2355710@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 30-11-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: The Physics of a “Smart” Bio‐Gel: SPEAKER: Dr. Roy Beck, University of California Santa Barbara  ABSTRACT/COMMENTS: Understanding biological systems poses huge theoretical and  experimental challenges, attributable to their complexity,  dynamics and many different elementary lengths scales involved  in their interactions. These interactions scale from specific  atomic-scale covalent bonds through non-specific long-ranged  electrostatics. The complexity of biological systems is multi -scaled as well, as even a single cell is composed from many  different, very complicated building blocks.     In this talk, I will introduce our recent results about  neurofilament hydrogel, a very basic component of the neurons’  cytoskeleton. After we purify the three different subunit  proteins from bovine spinal-cord, they self-assemble to form  supra-macromolecules filaments with a ‘bottlebrush’ like geometry.  When assembled at high density, these neurofilaments form a  liquid crystalline hydrogels and serve as the matrix for the  neuron’s long processes (axons and dendrites). They impart  mechanical stability and act as structural scaffolds. Using  synchrotron small angle x ray scattering under osmotic pressure  coupled with various microscopy techniques, we directly measure  the interfilament forces responsible for the mechanical properties  of neurofilament hydrogels.    We show that the “smart” mechanical properties of neurofilament  gels can be tuned by variation of the subunit proteins and osmotic  pressure. Such modifications have been recorded for different  stages in neuron development and correlated to numerous  neurodegenerative iseases. Surprisingly, under certain  conditions, such as critical pressure or specific subunit  protein ratios, negatively net-charged and sterically repulsing  filaments show attractive interactions. We are able to explain  these results via a competition between long- and short-ranged  interactions, with a key combination from electrostatic interaction  between altering positive and negative charged residues along the  neuroflament brushes.        From nano at bgu.ac.il Wed Nov 25 09:12:27 2009 From: nano at bgu.ac.il (Nano) Date: Wed Nov 25 09:14:56 2009 Subject: [Phys-seminars] 2009-11-25 Reminder: Nnaotechnology seminar-Jeffrey Gordon Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Jeffrey Gordon 251109.doc Type: application/msword Size: 143872 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091125/402689f2/JeffreyGordon251109-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Jeffrey Gordon 251109.pdf Type: application/pdf Size: 97632 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091125/402689f2/JeffreyGordon251109-0001.pdf From ibar at bgu.ac.il Wed Nov 25 09:53:56 2009 From: ibar at bgu.ac.il (ilana) Date: Wed Nov 25 09:54:53 2009 Subject: [Phys-seminars] 2009-12-01 Lasers Seminar Message-ID: <000901ca6da4$709b4ad0$51d1e070$@ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 01-12-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: ????? ????? ??? ???? ????? ?? ?????? SPEAKER: ?"? ??? ????, ????? ????? ?????? ???? ABSTRACT/COMMENTS: ??????? ??? ?????? ?????? ?????? SLM TEM00, ????? ????? ??????? ?? ??????, ?????? ?"? ????? ??????. ?????? ??, ???????? ???? ?????????? Monte Carlo ?????? ?????? ??????? ????? ?? ????? ????, ????? ????? ???????? ?? ???????. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091125/f3f4e115/attachment.htm From physics at bgu.ac.il Wed Nov 25 14:42:26 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Wed Nov 25 14:42:28 2009 Subject: [Phys-seminars] 2009-11-25 Physical Chemistry Seminar Message-ID: <200911251242.OAA2425368@tzin.bgu.ac.il> Physical Chemistry Seminar DATE: 25-11-2009 TIME: 4:00pm (Wed) PLACE: Chemistry club (Building #29, room 307) TITLE: \"Aperiodic structures, order and disorder\" SPEAKER: Shelomo I. Ben-Abraham, Department of Physics, Ben-Gurion University of the Negev ABSTRACT/COMMENTS: I discuss some current issues in crystallography and materials science. After a brief reminder of quasiperiodicity I summarize the recent discussion on what is a crystal. The best up-to-date answer is that it is a solid whose Fourier spectrum has a pure point part; in other words, it shows Bragg peaks On the other hand, there is growing interest in quasiregular heterostructures. These are artificially fabricated layer structures according to certain deterministic algorithms based mainly of substitution sequences of which I quote some typical examples. Their Fourier spectra are of utmost interest. I also discuss the fuzzy notions of \"order and disorder\" and show ways to define and quantify them From ymeir at bgu.ac.il Thu Nov 26 10:54:57 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Thu Nov 26 10:55:00 2009 Subject: [Phys-seminars] 2009-12-03 Physics Colloquium Message-ID: <200911260854.KAA1299152@tzin.bgu.ac.il> Physics Colloquium DATE: 03-12-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: EMERGING SUPERCONDUCTIVITY IN NEARLY ANTI-FERROMAGNETIC CUPRATES SPEAKER: Prof. Guy Deutscher, Tel Aviv University ABSTRACT/COMMENTS: The High Temperature Superconductors discovered by Bednorz and Mueller derive from anti-ferromanetic cuprates by the addition of carriers that destroy the AF state and induce metallicity. Experiments indicating that as more carriers are added the superconducting pairing mechanism may evolve from real space pairing to the conventional BCS k-space pairing will be reviewed. A recent proposal that the emergence of superconductivity is preceded by strong lattice disorder (1) is in agreement with recent experimental observations. Refreshments are served at 3:20pm From danrich at bgu.ac.il Thu Nov 26 18:19:18 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Thu Nov 26 18:19:20 2009 Subject: [Phys-seminars] 2009-12-02 Nanotechnology Workshop Message-ID: <200911261619.SAA2548515@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 02-12-2009 TIME: 12:00 (noon) PLACE: Chemistry Dept. Seminar Room (Building #29, room 307) TITLE: Probing Protein Self-Assembly and Interactions: The Elasticity of ‘Bottlebrush’ Neurofilament Proteins SPEAKER: Dr. Roy Beck, ABSTRACT/COMMENTS: The multi-component nature that is inherent in biological systems presents a significant challenge to both the theoretical description an experimental study. This is attributable to their complexity, dynamics and many different elementary lengths scales involve in their interactions. Though complex, some biological systems are modeled using simplified physical assumption, in many cases adopted from soft-condensed matter, and polymer physics principles. Here, I will introduce our recent single macromolecule measurments on neurofilaments, a very basic component of the neurons’ cytoskeleton. After we purify the three different subunit proteins from bovine spinal-cord, they self-assemble to form supra-macromolecules filaments with a ‘bottlebrush’-like geometry. Clinical studies show that subunit proteins ratio is changing during different stages in of the neuron development and correlaed to numerous neurodegenerative diseases. Therefore, we studied the effect of the subunit ratio have on the single filament configuration using atomic force microscopy and innovatve immobilization technique. We show that the neurofilament apparent configurations are tuned by variation in the assembled subunit proteins ratio and in cotrary trend to available polymer theories. The results are in agreement with our recent microscopy and small-angle x-ray scattering data on condensed neurofilaments hydrogel. We are able to explain these results as a competition between long- and short-ranged interactions, with a key combination from attractive electrostatic interaction between alternating positive and negative charged residues alng the neurofilament brushes. From danrich at bgu.ac.il Thu Nov 26 18:27:49 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Thu Nov 26 18:27:51 2009 Subject: [Phys-seminars] 2009-12-02 Nanotechnology Workshop Message-ID: <200911261627.SAA2543646@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 02-12-2009 TIME: 12:00 (noon) PLACE: Chemistry Dept. Seminar Room (Building #29, room 307) TITLE: Probing Protein Self-Assembly and Interactions: The Elasticity of ‘Bottlebrush’ Neurofilament Proteins SPEAKER: Dr. Roy Beck, University of California, Santa Barbara, ABSTRACT/COMMENTS: The multi-component nature that is inherent in biological systems presents a significant challenge to both the theoretical description an experimental study. This is attributable to their complexity, dynamics and many different elementary lengths scales involve in their interactions. Though complex, some biological systems are modeled using simplified physical assumption, in many cases adopted from soft-condensed matter, and polymer physics principles. Here, I will introduce our recent single macromolecule measurments on neurofilaments, a very basic component of the neurons’ cytoskeleton. After we purify the three different subunit proteins from bovine spinal-cord, they self-assemble to form supra-macromolecules filaments with a ‘bottlebrush’-like geometry. Clinical studies show that subunit proteins ratio is changing during different stages in of the neuron development and correlaed to numerous neurodegenerative diseases. Therefore, we studied the effect of the subunit ratio have on the single filament configuration using atomic force microscopy and innovatve immobilization technique. We show that the neurofilament apparent configurations are tuned by variation in the assembled subunit proteins ratio and in cotrary trend to available polymer theories. The results are in agreement with our recent microscopy and small-angle x-ray scattering data on condensed neurofilaments hydrogel. We are able to explain these results as a competition between long- and short-ranged interactions, with a key combination from attractive electrostatic interaction between alternating positive and negative charged residues alng the neurofilament brushes. From ibar at bgu.ac.il Tue Dec 1 16:30:38 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Dec 1 16:31:38 2009 Subject: [Phys-seminars] 2009-12-08 Lasers Seminar Message-ID: <008a01ca7292$d9f08250$8dd186f0$@ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 08-12-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: ULTRAFAST and ULTRASLOW DYNAMICS of MOLECULAR SUPEREXCITED STATES SPEAKER: Dr. Daniel Strasser, Institute of Chemistry, The Hebrew University of Jerusalem ABSTRACT/COMMENTS: I will discuss optically excited ultrafast and ultraslow dynamics of superexcited molecular ions. Superexcited states are by definition electronic states that lie above the threshold energy to eject an electron to the ionization continuum. While optical excitation of neutral superexcited states requires photon energies in the EUV range, superexcited states of anionic molecules can be accessed also with NIR - VIS range photon energies. Once excited, superexcited states decay predominantly by emission of the excited electron to the continuum, and thus releasing the excess energy in the system. In atomic systems, the only competing relaxation pathway by radiative decay, is relatively slow and is negligible in most cases. However, in molecular systems an additional decay channel is opened by the possibility to dissipate the excess energy into nuclear motion, typically resulting in molecular fragmentation. The resulting competition of electronic and nuclei motion dynamics on comparable time scales offers an intrinsically non Born-Openheimer (BO) test ground to extend our understanding of dynamics beyond the BO approximation that are key to understanding many ultrafast molecular reactions. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091201/1f80e79f/attachment.htm From nano at bgu.ac.il Wed Dec 2 08:47:34 2009 From: nano at bgu.ac.il (Nano) Date: Wed Dec 2 08:49:55 2009 Subject: [Phys-seminars] 2009-12-02 Reminder: Nnaotechnology seminar- Roy Beck Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Roy Beck 021209.doc Type: application/msword Size: 145408 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091202/62175667/RoyBeck021209-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Roy Beck 021209.pdf Type: application/pdf Size: 96237 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091202/62175667/RoyBeck021209-0001.pdf From manassen at bgu.ac.il Wed Dec 2 11:16:06 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Wed Dec 2 11:16:08 2009 Subject: [Phys-seminars] 2009-12-06 Condensed Matter Seminar Message-ID: <200912020916.nB29G6CL008601@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 06-12-2009 TIME: 14:00 (Sun) PLACE: Physics building (#54) room 207 TITLE: General relativity and graphene SPEAKER: Prof. Maria Vozmediano , Instituto de Ciencia de Materiales de Madrid, Spain ABSTRACT/COMMENTS: Comment: Please note special date and hour. Abstract: The main conceptual advances in physics have usually been prompted by discoveries in different branches of physics simultaneously. In the past century, Statistical physics, quantum field theory and condensed matter have had their main developments in parallel with the best physicists (Feynman, Landau, Wigner) contributing to all. The recent experimental discovery of graphene, a two-dimensional crystal made of a single carbon layer in 2004 provides a new and unexpected bridge between condensed matter and high-energy physics. The graphene samples used in the experiments show corrugations that can influence the transport properties of the system. The low energy excitations around the Fermi level in graphene are relativistic Dirac fermions. This fact calls for the possibility of using general relativity techniques to study the influence of the curvature of the background sheet on the electronic properties of the samples. Topological defects in graphene give rise to singular metrics: Disclinations mimic cosmic strings and dislocations introduce torsion in the space, a rare property in general relativity that can result in a feedback for cosmologists. These defects give rise to long range correlated disorder that contribute to non-universal minimal conductivity of the samples. From meirav at bgu.ac.il Wed Dec 2 17:34:14 2009 From: meirav at bgu.ac.il (meirav@bgu.ac.il) Date: Wed Dec 2 17:34:17 2009 Subject: [Phys-seminars] 2009-12-07 Particles and Fields Seminar Message-ID: <200912021534.nB2FYE1r003184@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 07-12-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Analyticity and high energy scattering amplitudes in N=4 SUSY SPEAKER: Prof. Lev Lipatov, St. Petersburg Nucl. Phys. Inst. ABSTRACT/COMMENTS: I review the BFKL approach for the calculation of scattering amplitudes in QCD. It is based on an intensive use of analyticity, unitarity and crossing symmetry of the S-matrix. The BFKL Pomeron turns out to be a composite state of two reggeized gluons. The integral kernel of the equation for the Pomeron wave function in the next-to-leading approximation has remarkable properties in N=4 SUSY. Here the Pomeron coincides with the reggeized graviton. It is shown, that the BDS ansatz for production amplitudes does not contain the Mandelstam cut contribution. This contribution is calculated in the leading logarithmic approximation. The final result has simple analyticity and factorization properties. From manassen at bgu.ac.il Thu Dec 3 09:49:07 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Thu Dec 3 09:49:09 2009 Subject: [Phys-seminars] 2009-12-07 Condensed Matter Seminar Message-ID: <200912030749.nB37n7LF025729@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 07-12-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Ordered Models for Disordered Matter SPEAKER: Dr. Yair Shokef, Physics of Complex Systems Weizmann Institute of Science Rehovot 76100, Israel ABSTRACT/COMMENTS: From ymeir at bgu.ac.il Thu Dec 3 10:39:51 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Thu Dec 3 10:39:53 2009 Subject: [Phys-seminars] 2009-12-10 Physics Colloquium Message-ID: <200912030839.nB38dpBp029166@tzin.bgu.ac.il> Physics Colloquium DATE: 10-12-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: To send or receive but not both: An inter-cellular signaling switch for multi-cellular pattern formation SPEAKER: David Sprinzak, California Institute of echnology ABSTRACT/COMMENTS: How complex patterns of cells are generated during embryonic development has been a central question in science for centuries. In the past few decades many of the molecular components involved in these processes (signaling molecules, genes, and proteins) and their interactions have been identified. While we can use this knowledge to draw a detailed interaction network of genes and proteins, it is often unclear how these genetic networks generate the observed patterns. In this talk, I will describe the experimental and theoretical analysis of a class of developmental processes that lead to ‘fine grained’ patterns: patterns with a typical length scale of one cell (e.g. alternating patterns of cell fates or sharp boundaries between regions of cells). In animals, many of these fine grained patterns rely on the Notch signaling pathway which is the canonical communication system between neighboring cells. We use quantitative time lapse microscopy of mammalian cells together with ma thematical modeling to study how the properties of the Notch signaling pathway affect pattern formation. We show how the Notch signaling pathway integrates extracellular and intracellular signals to generate a sharp switch between two mutually exclusive signaling states; a ‘sender’ state in which a cell can predominantly send signals, and a ‘receiver’ state in which a cell predominantly ‘receives’ signals. Furthermore, we show how this signaling switch can play an important role in the differentiation of neighboring cells into distinct fates in several developmental patterning processes. Finally, I will describe how the experimental and theoretical approach developed in this study can be generalized to address a variety of basic questions in developmental patterning that cannot easily be investigated with standard biological techniques. Refreshments are served at 3:20pm From meirav at bgu.ac.il Mon Dec 7 10:19:24 2009 From: meirav at bgu.ac.il (meirav@bgu.ac.il) Date: Mon Dec 7 10:19:27 2009 Subject: [Phys-seminars] 2009-12-07 Particles and Fields Seminar Message-ID: <200912070819.nB78JOms002785@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 07-12-2009 TIME: 13:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: SPEAKER: Lev Lipatov, ABSTRACT/COMMENTS: The time of the seminar has been changed to 13:00. From nano at bgu.ac.il Tue Dec 8 07:56:12 2009 From: nano at bgu.ac.il (Nano) Date: Tue Dec 8 07:58:34 2009 Subject: [Phys-seminars] 2009-12-09 No nanotechnology seminar this week Message-ID: -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091208/85b79a54/attachment.htm From ibar at bgu.ac.il Tue Dec 8 17:42:10 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Dec 8 17:43:12 2009 Subject: [Phys-seminars] 2009-12-15 Lasers Seminar Message-ID: <000001ca781d$014b7eb0$03e27c10$@ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 15-12-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Spatiotemporal Nonlinear Optical Diffraction SPEAKER: Alon Bahabad, Department of Physics and JILA, University of Colorado at Boulder and NIST, Boulder, Colorado 80309 USA ABSTRACT/COMMENTS: Since its inception in the early 1960s, a nonlinear optical diffraction technique known as Quasi-phase-matching (QPM) was used to mitigate the dispersion-born phase mismatch in optical processes involving beams with different frequencies. QPM is relevant to many areas of photonic research and applications as it allows among other things: efficient frequency conversion, beam and pulse shaping, multi-harmonic generation, high-harmonic-generation, all-optical processing and generation of entangled photons. Since QPM was first demonstrated using a one-dimensional periodic modulation it evolved to include quasi-periodic modulations, random modulations, two-dimensional structures and also non-uniform structures. In all of its various forms QPM always used a spatial-modulation (usually of the nonlinear electric susceptibility) to account for the momentum imbalance that dispersion imposes on the interacting photons. Here we present a fundamental extension of quasi phase matching where spatiotemporal nonlinear optical diffraction allows for both energy and momentum imbalance to be corrected-for. In the regular, traditional, QPM process, the spatial modulation breaks the otherwise continuous spatial translational symmetry, experienced by the photons, which leads to the requirement of exact momentum conservation. Adding a temporal modulation allows to replace the usual requirement for exact conservation of energy with a more flexible condition which depends on the exact nature of the temporal modulation used. In this case the phase mismatch caused by dispersion can be distributed between the momentum and energy four-momentum components of the interacting photons. This spatiotemporal QPM establishes a framework for designing and analyzing phase-matching schemes based on dynamic modulations. The most notable example for using such a dynamic modulation is an all-optical QPM scheme which uses counter propagating light pulses to establish a moving modulation of the nonlinear interaction. Spatiotemporal QPM would allow unique schemes which are impossible with the regular spatial QPM, especially when parameters of the nonlinear interaction are changing dynamically. Such an important case is the extreme non linear process of High-Harmonic-Generation, in which an intense laser pulse creates a broad-bandwidth of up-converted radiation in the extreme UV and soft X-ray regions of the spectrum. Here, the conditions for the generation of photons with specific frequencies as well as the index of refraction of the fundamental change dynamically on time scales which are much shorter than the fundamental pulse width. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091208/80dd77d7/attachment.htm From ibar at bgu.ac.il Tue Dec 8 22:56:22 2009 From: ibar at bgu.ac.il (Ilana Bar) Date: Tue Dec 8 22:56:26 2009 Subject: [Phys-seminars] 2009-12-15 Lasers Seminar Message-ID: ANNOUNCEMENT==> Lasers Seminar DATE: 15-12-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Spatiotemporal Nonlinear Optical Diffraction SPEAKER: Dr. Alon Bahabad, Department of Physics and JILA, University of Colorado at Boulder and NIST, Boulder, Colorado 80309 USA ABSTRACT/COMMENTS: Since its inception in the early 1960s, a nonlinear optical diffraction technique known as Quasi-phase-matching (QPM) was used to mitigate the dispersion-born phase mismatch in optical processes involving beams with different frequencies. QPM is relevant to many areas of photonic research and applications as it allows among other things: efficient frequency conversion, beam and pulse shaping, multi-harmonic generation, high-harmonic-generation, all-optical processing and generation of entangled photons. Since QPM was first demonstrated using a one-dimensional periodic modulation it evolved to include quasi-periodic modulations, random modulations, two-dimensional structures and also non-uniform structures. In all of its various forms QPM always used a spatial-modulation (usually of the nonlinear electric susceptibility) to account for the momentum imbalance that dispersion imposes on the interacting photons. Here we present a fundamental extension of quasi phase matching where spatiotemporal nonlinear optical diffraction allows for both energy and momentum imbalance to be corrected-for. In the regular, traditional, QPM process, the spatial modulation breaks the otherwise continuous spatial translational symmetry, experienced by the photons, which leads to the requirement of exact momentum conservation. Adding a temporal modulation allows to replace the usual requirement for exact conservation of energy with a more flexible condition which depends on the exact nature of the temporal modulation used. In this case the phase mismatch caused by dispersion can be distributed between the momentum and energy four-momentum components of the interacting photons. This spatiotemporal QPM establishes a framework for designing and analyzing phase-matching schemes based on dynamic modulations. The most notable example for using such a dynamic modulation is an all-optical QPM scheme which uses counter propagating light pulses to establish a moving modulation of the nonlinear interaction. Spatiotemporal QPM would allow unique schemes which are impossible with the regular spatial QPM, especially when parameters of the nonlinear interaction are changing dynamically. Such an important case is the extreme non linear process of High-Harmonic-Generation, in which an intense laser pulse creates a broad-bandwidth of up-converted radiation in the extreme UV and soft X-ray regions of the spectrum. Here, the conditions for the generation of photons with specific frequencies as well as the index of refraction of the fundamental change dynamically on time scales which are much shorter than the fundamental pulse width. Prof. I. Bar Department of Physics Ben-Gurion University of the Negev Beer Sheva 84105 ISRAEL? -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091208/b258406a/attachment-0001.htm From manassen at bgu.ac.il Thu Dec 10 09:00:38 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Thu Dec 10 09:00:40 2009 Subject: [Phys-seminars] 2009-12-14 Condensed Matter Seminar Message-ID: <200912100700.nBA70cHJ003870@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 14-12-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: High Tc superfluidity in bilayer graphene SPEAKER: Dr. Rafi Bistritzer, University of Texas at Austin ABSTRACT/COMMENTS: Condensation of electron-hole pairs in bilayer systems is a spectacular quantum phenomena in which coherence between two physically separated layers emerges spontaneously at low temperatures. To date this phenomena has been unambiguously observed only in semiconductor bilayers, and in these systems only at sub-kelvin temperatures and strong magnetic fields. In this talk I will discuss the possibility of pair condensation in bilayer graphene and explain why the critical temperature of this system can be exceptionally high. I will also elaborate on the influence of disorder and screening on the bilayer mean field and Kosterlitz-Thouless critical temperatures. I will show that, in some respects, superfluidity in bilayer graphene is distinct from all other known examples of superfluid behavior. From ymeir at bgu.ac.il Thu Dec 10 10:39:16 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Thu Dec 10 10:39:20 2009 Subject: [Phys-seminars] 2009-12-17 Physics Colloquium Message-ID: <200912100839.nBA8dGkA010657@tzin.bgu.ac.il> Physics Colloquium DATE: 17-12-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Strong interactions at high energies: from deep inelastic scattering to heavy ion collisions SPEAKER: Michael Lublinsky, Department of Physics, Ben Gurion University ABSTRACT/COMMENTS: Strong interactions are described by a non-abelian field theory, known as quantum chromodynamics (QCD). Some aspects of QCD, relevant to high energy collider experiments, will be presented. In particular, I will talk about QCD evolution equations, the phenomenon of gluon saturation, the quark-gluon plasma and its dual description in terms of five-dimensional gravity. Refreshments are served at 3:20pm From danrich at bgu.ac.il Thu Dec 10 10:55:14 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Thu Dec 10 10:55:16 2009 Subject: [Phys-seminars] 2009-12-16 Nanotechnology Workshop Message-ID: <200912100855.nBA8tE6S011721@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 16-12-2009 TIME: 12:00 (noon) PLACE: Chemistry Dept. Seminar Room (Building #29, room 307) TITLE: Synthesis, Characterization and Electronic Applications of Chemically Converted Graphene SPEAKER: Prof. Richard Kaner, Departments of Chemistry and Materials Science & Eng., University of California, Los Angeles ABSTRACT/COMMENTS: Single layer graphene is of great interest for electronic applications as an atomically thin, zero band gap semiconductor. Experimental results so far have been limited due to the difficulty of creating large, single layer samples. Here we report a competitive approach to the large-scale production of single layer chemically converted graphene (CCG). By dispersing graphite oxide paper in pure hydrazine, we are able to remove oxygen functionalities while preserving the integrity and restoring the planar geometry of single sheets. The CCG sheets produced with this method have among the largest areas of any yet reported (up to 20 x 40 m), making them relatively straightforward to process. Field effect devices have been fabricated by conventional photolithography and display currents that are three orders of magnitude higher than those previously reported for CCG. The versatility of solution processing also enables single layer graphene sheets to be registered using a PDMS stamping technique. Through surface energy manipulation, large-scale registration of graphene is now possible. Raman spectroscopy has been used to confirm uniform registration across large areas. Due to the large size of these sheets, comprehensive studies including optical microscopy, AFM, SEM and FET device characterization can all be performed on the same specimen. By combining graphene and carbon nanotubes, flexible, conducting, transparent windows can be made. This solution processing of carbon-based materials thus holds great promise for nanoelectronic applications. From danrich at bgu.ac.il Thu Dec 10 11:01:07 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Thu Dec 10 11:01:09 2009 Subject: [Phys-seminars] 2009-12-16 Nanotechnology Workshop Message-ID: <200912100901.nBA9178K012054@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 16-12-2009 TIME: 12:00 (noon) PLACE: Chemistry Dept. Seminar Room (Building #29, room 307) TITLE: Synthesis, Characterization and Electronic Applications of Chemically Converted Graphene SPEAKER: Prof. Richard Kaner, Departments of Chemistry and Materials Science & Eng., University of California, Los Angeles ABSTRACT/COMMENTS: Single layer graphene is of great interest for electronic applications as an atomically thin, zero band gap semiconductor. Experimental results so far have been limited due to the difficulty of creating large, single layer samples. Here we report a competitive approach to the large-scale production of single layer chemically converted graphene (CCG). By dispersing graphite oxide paper in pure hydrazine, we are able to remove oxygen functionalities while preserving the integrity and restoring the planar geometry of single sheets. The CCG sheets produced with this method have among the largest areas of any yet reported (up to 20 x 40 microns), making them relatively straightforward to process. Field effect devices have been fabricated by conventional photolithography and display currents that are three orders of magnitude higher than those previously reported for CCG. The versatility of solution processing also enables single layer graphene sheets to be registered using a PDMS stamping technique. Through surface energy manipulation, large-scale registration of graphene is now possible. Raman spectroscopy has been used to confirm uniform registration across large areas. Due to the large size of these sheets, comprehensive studies including optical microscopy, AFM, SEM and FET device characterization can all be performed on the same specimen. By combining graphene and carbon nanotubes, flexible, conducting, transparent windows can be made. This solution processing of carbon-based materials thus holds great promise for nanoelectronic applications. From nano at bgu.ac.il Thu Dec 10 11:54:56 2009 From: nano at bgu.ac.il (Nano) Date: Thu Dec 10 11:57:21 2009 Subject: [Phys-seminars] 2009-12-16 Nanotechnology seminar- Richard Kaner Message-ID: <12B93D9066774BDE83A8A6FAB1E00908@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Richard Kaner 161209.doc Type: application/msword Size: 143872 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091210/5f083963/RichardKaner161209-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Richard Kaner 161209.pdf Type: application/pdf Size: 107781 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091210/5f083963/RichardKaner161209-0001.pdf From meirav at bgu.ac.il Thu Dec 10 13:34:50 2009 From: meirav at bgu.ac.il (meirav@bgu.ac.il) Date: Thu Dec 10 13:34:52 2009 Subject: [Phys-seminars] 2009-12-14 Particles and Fields Seminar Message-ID: <200912101134.nBABYo4A022136@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 14-12-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Small Field Models of Inflation SPEAKER: Ido Ben-Dayan , BGU ABSTRACT/COMMENTS: I analyze small field inflationary models. I discuss their possible realization in string theory in the supergraqvity approximation. After that I analyze their predictions in general (not limited to string theory origin). I demonstrate that at the price of some tuning such models possess interesting phenomena such as gravitational wave signal and running spectral index at a detectable level. Hence, such models are the best candidates of explaining such phenomena without any additional assumptions beyond regular slow-roll. Finally I discuss running of the spectral index from effective field theory, and show that for a consistent theory the running gives a strong bound or even a prediction on the scale of inflation. From physics at bgu.ac.il Mon Dec 14 10:42:21 2009 From: physics at bgu.ac.il (physics@bgu.ac.il) Date: Mon Dec 14 10:42:25 2009 Subject: [Phys-seminars] 2009-12-23 Astrophysics and Cosmology Seminar Message-ID: <200912140842.nBE8gLo4013326@tzin.bgu.ac.il> Astrophysics and Cosmology Seminar DATE: 23-12-2009 TIME: 12:00 noon (Wed) PLACE: Physics building (#54) room 207 TITLE: Highlights from Fermi Gamma-Ray Space Telescope observations of Gamma-Ray Bursts SPEAKER: Jonathan Granot, University of Hertfordshire ABSTRACT/COMMENTS: During its first year of operation the Fermi Gamma-Ray Space Telescope has more than doubled the number of Gamma-Ray Bursts (GRBs) detected at high photon energies (>100 MeV). Thanks to the very wide energy range covered by Fermi\'s Gamma-ray Burst Monitor (GBM; 8 keV to 40 MeV) and Large Area Telescope (LAT; 25 MeV to >300 GeV) it has measured the prompt GRB emission spectrum over an unprecedentedly large energy range (from ~8 keV to ~30 GeV). I will present highlights from Fermi GRB observations focusing mainly on the prompt emission phase. Interesting new observations will be discussed along with some of their possible implications, including: (i) a strict limit on a possible variation of the speed of light with photon energy (for the first time beyond the Planck scale for a linear energy dependence from direct arrival time measurements), (ii) lower-limits on the bulk Lorentz factor of the GRB outflow (of ~1000 for the brightest Fermi LAT GRBs), (iii) the detection (or in other cases, lack thereof) of a distinct spectral component at high (and sometimes also at low) energies, and possible implications for the prompt GRB emission mechanism, (iv) the later onset (and longer duration) of the high-energy emission (> 100 MeV) compared to the low-energy (< 1 MeV) emission that is seen in most Fermi-LAT GRBs, (v) what can we learn from the Fermi-LAT GRB detection rate, and comparing the high-energy emission properties of GRBs from the short and long duration classes. From meirav at bgu.ac.il Wed Dec 16 08:22:40 2009 From: meirav at bgu.ac.il (meirav@bgu.ac.il) Date: Wed Dec 16 08:22:44 2009 Subject: [Phys-seminars] 2009-12-21 Particles and Fields Seminar Message-ID: <200912160622.nBG6MeKU015222@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 21-12-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Gluon scattering amplitudes and classical strings in AdS x S SPEAKER: Nadav Drukker , Humboldt-Universität, Berlin ABSTRACT/COMMENTS: It has been known for a long time that string scattering at high energy in flat space is dominated by classical string solutions. Recently it was realized by Alday and Maldacena that the analog statement for strings in AdS space leads to a simple answer for gluon scattering in the dual gauge theory. I will review this correspondence and extend it to some richer scattering problems. From ibar at bgu.ac.il Wed Dec 16 08:51:51 2009 From: ibar at bgu.ac.il (ilana) Date: Wed Dec 16 08:53:01 2009 Subject: [Phys-seminars] 2009-12-22 Lasers Seminar Message-ID: <008d01ca7e1c$3eebdf30$bcc39d90$@ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 22-12-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: To transmit, or not to transmit, that is the question: the role of surface plasmons in extraordinary transmission of metal nano-slit devices, and beyond SPEAKER: Prof. Ronen Rapaport, The Racah Institute of Physics and The Department of Applied Physics, The Hebrew University, Jerusalem ABSTRACT/COMMENTS: When light impinges on a thin metal slit array, where the slits width are much smaller than the wavelength of the incoming light, there are certain wavelengths for which the transmission is much larger than what one would naively expect from just the geometrical ratio of the slits to the metal area. In fact, it turns out that almost all the energy is somehow channeled through the tiny slits to the other side, which is a bit odd (and rather cool). The underlying mechanism for such extraordinary transmission is generally attributed to a combination of coupled surface plasmons and gap-cavity excitations. In this talk I will present some recent results that experimentally show a different kind of extraordinary transmission, without the kind help of these celebrity surface plasmons. I will also discuss the possibilities of utilizing the strong local fields in such devices for various linear and nonlinear optical applications. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091216/35ee33b3/attachment.htm From nano at bgu.ac.il Wed Dec 16 09:40:39 2009 From: nano at bgu.ac.il (Nano) Date: Wed Dec 16 09:43:20 2009 Subject: [Phys-seminars] 2009-12-16 Reminder: Nnaotechnology seminar-Richard Kaner Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Richard Kaner 161209.pdf Type: application/pdf Size: 107781 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091216/59610ea1/RichardKaner161209-0001.pdf -------------- next part -------------- A non-text attachment was scrubbed... Name: Richard Kaner 161209.doc Type: application/msword Size: 143872 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091216/59610ea1/RichardKaner161209-0001.doc From nano at bgu.ac.il Wed Dec 16 13:23:08 2009 From: nano at bgu.ac.il (Nano) Date: Wed Dec 16 13:25:36 2009 Subject: [Phys-seminars] 2009-12-23 Nnaotechnology seminar-Daphne Weihs Message-ID: <7C86297710A64FBAB133A3DE91144C95@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Daphne Weihs 231209.doc Type: application/msword Size: 144384 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091216/65f1f912/DaphneWeihs231209-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Daphne Weihs 231209.pdf Type: application/pdf Size: 108923 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091216/65f1f912/DaphneWeihs231209-0001.pdf From danrich at bgu.ac.il Thu Dec 17 17:47:01 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Thu Dec 17 17:47:04 2009 Subject: [Phys-seminars] 2009-12-23 Nanotechnology Workshop Message-ID: <200912171547.nBHFl1vC008304@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 23-12-2009 TIME: 12:00 (noon) PLACE: Chemistry club (Building #29, room 307) TITLE: Experimental Evidence of Strong Anomalous Diffusion in Living Cells SPEAKER: Dr. Daphne Weihs, Department of Biomedical Engineering, Technion ABSTRACT/COMMENTS: We show that transport of polymeric particles embedded deep within living cancer cells exhibits strongly anomalous diffusion. The mean square displacement demonstrated super-diffusion with a scaling exponent of 1.25. That indicates active transport of particles in the cell, most likely due to molecular motors, and in accordance with previous studies. To further characterize the transport, we have calculated a range of time-dependent displacement moments. For each moment order q, a scaling exponent lambda(q) was extracted. Scaling exponents were non-linear with q, indicating that the motion is not scale-invariant. In addition, the quantity lambda(q)/q was non-decreasing, and thus fills the conditions for strong anomalous diffusion, presented here experimentally for the first time. Specifically, scaling exponents exhibited a bi-linear form with moment order, with slopes of ~0.6 at low q-values and ~0.8 at high ones. The bi-linearity indicates that particle motion is composed of sub-diffusive regimes separated by active flights; those were sub-ballistic, by the slope of 0.8, and were not separable using a directionality criterion based on an angle correlation function. We suggest that the sub-ballistic flights are associated with the small particles size used in this work (100-200 nm); small particles diffuse within the cytoplasm while being actively transported, resulting in sub-ballistic motion. Results are further discussed in terms of particle interactions with their microenvironment and dynamics of that environment. From manassen at bgu.ac.il Fri Dec 18 13:10:17 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Fri Dec 18 13:10:20 2009 Subject: [Phys-seminars] 2009-12-21 Condensed Matter Seminar Message-ID: <200912181110.nBIBAHeS006475@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 21-12-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: The Dynamics of Channeled Vortex Motion SPEAKER: Mr. Ilan Barboy, Dept. of Physics, Ben Gurion University ABSTRACT/COMMENTS: Coherent effects in vortex motion along artificial laser processed channels of easy vortex motion in thin epitaxial YBCO films have been investigated by means of Raman, magneto-optics and transport measurements. Quasi Josephson effects manifesting themselves as constant current steps in I-V characteristics of bridges containing laser-fabricated vortex channels prove the coherent nature of the channeled vortex motion. From ymeir at bgu.ac.il Sun Dec 20 23:03:55 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Sun Dec 20 23:03:58 2009 Subject: [Phys-seminars] 2009-12-24 Physics Colloquium Message-ID: <200912202103.nBKL3tok011278@tzin.bgu.ac.il> Physics Colloquium DATE: 24-12-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Many body quantum interference: seeing strongly correlated states of ultra-cold atoms SPEAKER: Ehud Altman, the Weizmann Institute ABSTRACT/COMMENTS: Ultracold atoms trapped by optical lattice potentials or confined to low dimensions can realize interesting strongly correlated quantum states. When the atoms are released from their traps they expand freely, collective carrying with them a memory of the intricate correlations that characterized their original many-body state in the trap. The mapping between correlations in the trap and observable fluctuations in the expanding cloud occurs via many-body interference effects during the expansion. I will show how such \"quantum noise interferometry\" can be applied to shed light on novel quantum states from low dimensional quantum liquids to disordered systems. Refreshments are served at 3:20pm From ibar at bgu.ac.il Tue Dec 22 17:21:48 2009 From: ibar at bgu.ac.il (ilana) Date: Tue Dec 22 17:22:59 2009 Subject: [Phys-seminars] 2009-12-29 Lasers Seminar Message-ID: <001401ca831a$7a8b5360$6fa1fa20$@ac.il> ANNOUNCEMENT==> Lasers Seminar DATE: 29-12-2009 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Periodic, Quasi-Periodic and Random Nonlinear Photonic Structures SPEAKER: Prof. Ady Arie, Department of Physical Electronics, Tel-Aviv University, Tel-Aviv ABSTRACT/COMMENTS: Nonlinear photonic crystals are materials in which the second order susceptibility is modulated in an ordered fashion, usually in one or two dimensions, while the linear susceptibility remains constant. These crystals are significantly different than the more common photonic crystals, in which the linear susceptibility is modulated. The modulation of the material's nonlinearity is useful for efficient nonlinear frequency conversion, since it provides a method for compensating the phase mismatch between the interacting waves. Moreover, it enables to add new functions, such as all-optical switching, polarization rotation, beam shaping and beam control. In this talk I will discuss wave interactions in these structures, modulation techniques and some recent examples of functional nonlinear devices. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091222/61064fd1/attachment.htm From nano at bgu.ac.il Wed Dec 23 09:31:20 2009 From: nano at bgu.ac.il (Nano) Date: Wed Dec 23 09:34:04 2009 Subject: [Phys-seminars] 2009-12-23 Reminder: Nnaotechnology seminar-Daphne Weihs Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Daphne Weihs 231209.pdf Type: application/pdf Size: 108937 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091223/216d08bd/DaphneWeihs231209-0001.pdf -------------- next part -------------- A non-text attachment was scrubbed... Name: Daphne Weihs 231209.doc Type: application/msword Size: 144384 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091223/216d08bd/DaphneWeihs231209-0001.doc From ymeir at bgu.ac.il Wed Dec 23 13:28:17 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Wed Dec 23 13:28:18 2009 Subject: [Phys-seminars] 2009-12-31 Physics Colloquium Message-ID: <200912231128.nBNBSHer008882@tzin.bgu.ac.il> Physics Colloquium DATE: 31-12-2009 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Gravity and the Shape of Turbulence SPEAKER: Yaron Oz, School of Physics and Astronomy, Tel Aviv University ABSTRACT/COMMENTS: The dynamics of fluids is a long standing challenge that remained as an unsolved problem for centuries. Understanding its main features, chaos and turbulence, is likely to provide an understanding of the principles and non-linear dynamics of a large class of systems far from equilibrium. We consider a conceptually new viewpoint to study these features using black hole dynamics. Since the gravitational field is characterized by a curved geometry, the gravity variables provide a geometrical framework for studying the dynamics of fluids: A geometrization of turbulence. Refreshments are served at 3:20pm From avivaf at bgu.ac.il Wed Dec 23 15:03:29 2009 From: avivaf at bgu.ac.il (avivaf@bgu.ac.il) Date: Wed Dec 23 17:04:19 2009 Subject: [Phys-seminars] 2010-01-20 Special Seminar Message-ID: <200912231303.nBND3Txb015436@tzin.bgu.ac.il> Special Seminar DATE: 20-01-2010 TIME: 14:30 PLACE: Build 54, Room 207 TITLE: High spin super- and hyperdeformed isomeric states and long-lived superheavy elements SPEAKER: Prof. Amnon Marinov, Dept. of Physics, Hebrew University, Jerusalem ABSTRACT/COMMENTS: From hbaruch at bgu.ac.il Wed Dec 23 19:14:48 2009 From: hbaruch at bgu.ac.il (hbaruch@bgu.ac.il) Date: Wed Dec 23 19:14:53 2009 Subject: [Phys-seminars] 2009-12-29 Condensed Matter Seminar (Special) Message-ID: <200912231714.nBNHEmVh032463@tzin.bgu.ac.il> Condensed Matter Seminar (Special) DATE: 29-12-2009 TIME: 2:00pm (Tuesday) -- note special timing PLACE: Physics building (#54) room 207 TITLE: Deadly competition between sibling bacterial colonies SPEAKER: Dr. Avraham Be\'er, Center for Nonlinear Dynamics, University of Texas at Austin ABSTRACT/COMMENTS: As a result of stress due to nutrient limitation or antibiotics, competing individual bacteria within a single colony may lyse sibling cells to release nutrients (cannibalism) or DNA (fratricide). However, we have recently shown that competition is not limited to individuals, but can occur at the colony level. In response to the presence of an encroaching sibling colony, Paenibacillus dendritiformis bacteria secrete a lethal protein, lysing cells at the interface between the colonies. Analysis of the proteins secreted by these competing sibling colonies, combined with a mathematical model, show how colonies maintain their growth by self-regulating the secretion of two significant proteins: subtilisin (a growth promoter), and Slf (a lethal protein). The results also explain why a single colony is not inhibited by its own secretions. From meirav at bgu.ac.il Wed Dec 23 21:47:03 2009 From: meirav at bgu.ac.il (meirav@bgu.ac.il) Date: Wed Dec 23 21:47:05 2009 Subject: [Phys-seminars] 2009-12-28 Particles and Fields Seminar Message-ID: <200912231947.nBNJl3EV010137@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 28-12-2009 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: Lux et Lex: Optical Traps for β decay studies SPEAKER: Guy Ron, Nuclear Science Division Lawrence Berkeley National Lab ABSTRACT/COMMENTS: Neutral radioactive atoms trapped with laser light have become a standard tool of the trade for precision studies of beyond SM physics. β decay stud- ies, in particular, offer the possibility of detecting deviations from standard model predictions of the weak interaction. The development of the Soreq Applied Research Accelerator Facility (SARAF) promises the possibility of developing such an active research effort in Israel. I will present a general overview of optical traps and their use for weak interaction studies. I will further present the Berkeley 21Na trapping experiment, recent experimental results, and future plans. From manassen at bgu.ac.il Thu Dec 24 11:18:22 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Thu Dec 24 11:18:25 2009 Subject: [Phys-seminars] 2009-12-28 Condensed Matter Seminar Message-ID: <200912240918.nBO9IM6Y020749@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 28-12-2009 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Applications of conformal field theory methods to nonequilibrium transport through nanostructures SPEAKER: Dr. Eran Sela, University of British Columbia ABSTRACT/COMMENTS: Quantum impurity problems are among the few nontrivial problems describing strongly correlated condensed matter systems that are amenable to exact solutions. Due to recent advances in nanofabrication techniques, predictions from the conformal field theory (CFT) approach, such as nontrivial scaling exponents, can be tested by quantum dot experiments. A major challenge on which my talk focuses is the extension of exact methods to the nonequilibrium regime, in which quantum dot experiments are typically performed. Using CFT methods we solved exactly the problem of nonequilibrium transport through double quantum dots, obtaining exact results of experimental relevance for the full counting statistics of charge transport near a non-Fermi liquid critical point. Those results also imply a nontrivial effective charge of 2e, which can be probed by shot noise experiments. It remains an open problem to generalize the nonequilibrium solution to arbitrary quantum dot configurations. From danrich at bgu.ac.il Thu Dec 24 11:34:43 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Thu Dec 24 11:34:46 2009 Subject: [Phys-seminars] 2009-12-30 Nanotechnology Workshop Message-ID: <200912240934.nBO9Yhjh021776@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 30-12-2009 TIME: 12:00 (noon) PLACE: Chemistry Dept. Seminar Room (Building #29, Room 307) TITLE: Thermoelectricity at the Nanoscale SPEAKER: Dr. Yoni Dubi, Los Alamos National Laboratory ABSTRACT/COMMENTS: Thermoelectricity - the interplay between thermal gradients and electronic transport - is an old problem, dating back to Fourier in the 19th century. Recent advances in fabricating nano-scale systems have ignited new interest in thermo-electric effects, with the observation that nano-scale systems may have strong potential for thermo-electric applications. I will present a novel method for calculating properties of non-equilibrium nano-scale systems, based on the theory of open quantum systems. The method allows us to study in detail effects such as thermo-power generation across nano-scale junctions, and its strong dependence on geometry, disorder and interactions. I will show that the method enables us to calculate the electron temperature in such a non-equilibrium scenario, making it especially suitable to study the long-standing problem of the onset of Fourier\'s law, as applied to nano-scale metallic wires. I will end with some future prospects on how nano-scale thermoelectricity may be used in other contexts, such as spintronics and superconductivity. Relevant References: [1] Y. Dubi and M. Di Ventra, Nano Letters 9, 97 (2009). [2] Y. Dubi and M. Di Ventra, Phys. Rev. B 79, 115415 (2009). [3] Y. Dubi and M. Di Ventra, Phys. Rev. E 79, 042101 (2009). [4] Y. Dubi and M. Di Ventra, Phys. Rev. B. 79, 081302(R) (2009) [5] Y. Dubi and M. Di Ventra, arXiv:0907.2498 (2009). From nano at bgu.ac.il Thu Dec 24 12:32:40 2009 From: nano at bgu.ac.il (Nano) Date: Thu Dec 24 12:35:23 2009 Subject: [Phys-seminars] 2009-12-30 Nanotechnology seminar- Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Frank Brown+Yoni Dubi 301209.doc Type: application/msword Size: 147456 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091224/f5854916/FrankBrownYoniDubi301209-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Frank Brown+Yoni Dubi 301209.pdf Type: application/pdf Size: 116072 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091224/f5854916/FrankBrownYoniDubi301209-0001.pdf From danrich at bgu.ac.il Thu Dec 24 12:45:30 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Thu Dec 24 12:45:34 2009 Subject: [Phys-seminars] 2009-12-30 Nanotechnology Workshop Message-ID: <200912241045.nBOAjUFJ026649@tzin.bgu.ac.il> Nanotechnology Workshop DATE: 30-12-2009 TIME: 10:45 a.m. (Note Special Time) PLACE: Chemistry Dept. Seminar Room (Building #29, room 307) TITLE: Continuum Models for Membrane Dynamics SPEAKER: Prof. Frank Brown, Departments of Chemistry & Biochemistry and Physics, University of California at Santa Barbara ABSTRACT/COMMENTS: Simulation of biomembranes and model membrane systems over length and time scales relevant to cellular biology is not currently feasible with Molecular Dynamics or related atomically-detailed methods. Barring an unforeseen revolution in the computer industry, this situation will not change for several decades. Two aspects of membrane dynamics will be discussed: out-of-plane membrane undulations and in-plane flow/diffusion in inhomogeneous membrane systems. Both problems are treated within the context of continuum models, which allow access to length and time scales up to and beyond the micron and second regimes, using simple numerical methods. A number of effects relevant to the motion of integral membrane proteins as well as the dynamics of phase separation and domain fluctuations in multi-component lipid bilayers will be presented. From nano at bgu.ac.il Mon Dec 28 11:38:07 2009 From: nano at bgu.ac.il (Nano) Date: Mon Dec 28 11:40:42 2009 Subject: [Phys-seminars] 2010-01-03 : Nanotechnology special seminar- Marc Tornow Message-ID: <8A48BFBE795349DAAD12ED5C4E394231@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Marc Tornow 03012010.doc Type: application/msword Size: 146432 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091228/3c6a6f01/MarcTornow03012010-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Marc Tornow 03012010.pdf Type: application/pdf Size: 114543 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091228/3c6a6f01/MarcTornow03012010-0001.pdf From danrich at bgu.ac.il Mon Dec 28 12:46:17 2009 From: danrich at bgu.ac.il (danrich@bgu.ac.il) Date: Mon Dec 28 12:46:20 2009 Subject: [Phys-seminars] 2010-01-03 Special Nanotechnology Workshop Message-ID: <200912281046.nBSAkHuf024504@tzin.bgu.ac.il> Special Nanotechnology Workshop DATE: 03-01-2010 TIME: 12:00 (noon) PLACE: Chemistry Dept. Seminar Room (Building #29, room 307) TITLE: Integrating molecular electronics and label-free bio-sensing into silicon technology SPEAKER: Prof. Marc Tornow, Institute of Semiconductor Technology, Braunschweig University of Technology, Germany ABSTRACT/COMMENTS: In future microelectronic circuits a partial replacement of certain electronic functions by organic molecule junctions may become very likely. The realization of such concepts would benefit from a “monolithic” fabrication of nanoscale contacts on the same semiconductor wafer using current microelectronic process technology. Similarly, for applications addressing the label-free detection of biomolecules using the field effect in semiconductors a silicon based fabrication technology will be advantageous. This way, a possible integration into ‘lab-on-chip’ platforms may become feasible. In this talk, I will present two examples of our work in these areas. At first, this will address vertical nanogap electrode devices that comprise smooth metallic contact pairs situated at the sidewall of a pillar-like silicon based structure, with separations down to 5 nm. We have used these devices to study the electronic transport properties of 9-12 nm long, dithiolated oligo-phenylene-vinylene (OPV) “molecular wires” assembled onto the electrode gap from solution. A pronounced, non-linear current-voltage characteristic with a conductance gap of up to approx. ±1.5 V at low temperatures is observed. The magnitude of this gap can be correlated with the molecular structure at the termini of the molecules [1]. Secondly, I will focus on our recent efforts towards the label-free detection of DNA hybridization using silicon nanowires that have been functionalized in a novel manner using hydroxyalkylphosphonate monolayers. We studied the thin film properties of these organic layers in detail using several surface analysis techniques which indicated the presence of a dense monolayer on the native silicon oxide with thickness ~1 nm. The monolayer was further bio-functionalized with 12mer peptide nucleic acid (PNA) receptor molecules. 100 nm wide p-doped Si nanowires functionalized in this way allowed for the label-free detection of DNA hybridization in electrolyte buffer solution [2]. References: [1] R. Søndergaard, S. Strobel, E. Bundgaard, K. Norrman, A. G. Hansen, E. Albert, G. Csaba, P. Lugli, M. Tornow, F. C. Krebs, J. Mater. Chem. 19, 3899 (2009) [2] A. Cattani-Scholz, D. Pedone, M. Dubey, S. Neppl, B. Nickel, P. Feulner, J. Schwartz, G. Abstreiter, M. Tornow, ACS Nano 2, 1653–1660 (2008) . From ibar at bgu.ac.il Tue Dec 29 23:13:08 2009 From: ibar at bgu.ac.il (Ilana Bar) Date: Tue Dec 29 23:13:13 2009 Subject: [Phys-seminars] 2010-01-05 Lasers Seminar Message-ID: ANNOUNCEMENT==> Lasers Seminar DATE: 05-01-2010 TIME: 3:30pm (Tue) PLACE: Physics building (#54) room 207 TITLE: Experimental evidence for asymmetric noise-induced spin-flip transitions SPEAKER: Mr. Jonathan Coslovsky, Physics Department, Ben Gurion University of the Negev, ABSTRACT/COMMENTS: Trapping of neutral atoms in a magnetic trap is possible only for atoms in specific Zeeman states. Noise-induced spin-flip transitions can cause trapped atoms to be transferred to an un-trapped state and escape from the trap, thereby reducing the lifetime of the trapped atoms. In my talk, I will present experimental evidence, followed by a theoretical explanation, for asymmetric noise-induced spin-flip transition rates of cold atoms in a magnetic trap. I will also describe the experimental characterization process of a Bose-Einstein condensate, and will present some results. Prof. I. Bar Department of Physics Ben-Gurion University of the Negev Beer Sheva 84105 ISRAEL? -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091229/e1dc53f5/attachment.htm From nano at bgu.ac.il Wed Dec 30 09:14:57 2009 From: nano at bgu.ac.il (Nano) Date: Wed Dec 30 09:18:00 2009 Subject: [Phys-seminars] 2009-12-30 Reminder: Nanotechnology Workshop Message-ID: Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Frank Brown+Yoni Dubi 301209.doc Type: application/msword Size: 143360 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091230/75dc2c81/FrankBrownYoniDubi301209-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Frank Brown+Yoni Dubi 301209.pdf Type: application/pdf Size: 116072 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091230/75dc2c81/FrankBrownYoniDubi301209-0001.pdf From nano at bgu.ac.il Wed Dec 30 12:20:13 2009 From: nano at bgu.ac.il (Nano) Date: Wed Dec 30 12:22:49 2009 Subject: [Phys-seminars] 2010-01-06 : Nanotechnology seminar- Iddo Eliazar, Please notice the change in time Message-ID: <659D358E54E042CBB85A925B1F2A42AB@estinano> Skipped content of type multipart/alternative-------------- next part -------------- A non-text attachment was scrubbed... Name: Iddo Eliazar 06012010.doc Type: application/msword Size: 144384 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091230/4e422c35/IddoEliazar06012010-0001.doc -------------- next part -------------- A non-text attachment was scrubbed... Name: Iddo Eliazar 06012010.pdf Type: application/pdf Size: 104953 bytes Desc: not available Url : http://lists.bgu.ac.il/pipermail/phys-seminars/attachments/20091230/4e422c35/IddoEliazar06012010-0001.pdf From meirav at bgu.ac.il Wed Dec 30 21:51:20 2009 From: meirav at bgu.ac.il (meirav@bgu.ac.il) Date: Wed Dec 30 21:51:21 2009 Subject: [Phys-seminars] 2010-01-04 Particles and Fields Seminar Message-ID: <200912301951.nBUJpKhF005768@tzin.bgu.ac.il> Particles and Fields Seminar DATE: 04-01-2010 TIME: 10:00pm (Mon) PLACE: Physics building (#54) room 207 TITLE: More SUSY-breaking vacua in SQCD SPEAKER: Andrey Katz, University of Maryland ABSTRACT/COMMENTS: Anomalously small gaugino masses are a common feature of various models of direct gauge mediation. This problem is closely related to the vacuum structure of the theory. Unfortunately the ISS vacuum in massive SQCD is also affected by this problem. Nonetheless massive SQCD can have SUSY-breaking vacua which are qualitatively different from the ISS vacuum. In this talk I will focus on these vacua, which are meta-stable with respect to the ISS vacuum. I will show that the gaugino mass problem is properly addressed in these novel vacua, comment on some properties of these vacua and construct an example model of gauge mediation. From ymeir at bgu.ac.il Thu Dec 31 00:32:36 2009 From: ymeir at bgu.ac.il (ymeir@bgu.ac.il) Date: Thu Dec 31 00:32:39 2009 Subject: [Phys-seminars] 2010-01-07 Physics Colloquium Message-ID: <200912302232.nBUMWa19015291@tzin.bgu.ac.il> Physics Colloquium DATE: 07-01-2010 TIME: 3:30pm (Thu) PLACE: Physics building (#54) room 207 TITLE: Polarization fingerprints in the clear blue sky SPEAKER: Prof. Sir Michael Berry, University of Bristol ABSTRACT/COMMENTS: Daylight is polarized, the strength being greatest at points in the sky at right angles to the sun, and zero at four points: above and below the sun and anti-sun. The zero-polarization points are \'fingerprint\' singularities, around which the polarization direction makes a half-turn. Using elementary singularity theory, the polarization pattern across the whole sky can be described in a way that fits recent observations with an accuracy comparable to that of conventional elaborate multiple-scattering calculations. This recent work is a contribution to a story that started in 1817 and has been central to our understanding of polarized light. Refreshments are served at 3:20pm From manassen at bgu.ac.il Thu Dec 31 14:12:01 2009 From: manassen at bgu.ac.il (manassen@bgu.ac.il) Date: Thu Dec 31 14:12:04 2009 Subject: [Phys-seminars] 2010-01-04 Condensed Matter Seminar Message-ID: <200912311212.nBVCC1Xj028499@tzin.bgu.ac.il> Condensed Matter Seminar DATE: 04-01-2010 TIME: 11:30am (Mon) PLACE: Physics building (#54) room 207 TITLE: Inter-System Crossing in a Dissipative Three-Spin System SPEAKER: Dr. Sabine Tornow , Institute of Mathematical Physics (TU Braunschweig) ABSTRACT/COMMENTS: We present an extended Hubbard model with dissipation (dissipative Hubbard model) for analyzing the spin and electron dynamics of a donor-acceptor system representing a chromophore coupled to a radical in a solvent. The latter is modeled by a bosonic bath. After photoexcitation, the initial local singlet state on the chromophore can perform a transition to a local triplet state (inter-system crossing) dependent on the coupling to the dissipative environment, Coulomb interactions, exchange interactions, on-site-energies and hopping parameters. We investigate the rate of local triplet formation and calculate the time-dependent population probabilities of all electronic states with the Time-Dependent Numerical Renormalization Group. The investigation of the role of different parameters can help to tailor appropriate molecules and solvents, to study fundamental questions about controlling molecular spin-systems.