Astrophysics and Cosmology

Gravitational Lensing and High Redshift Galaxies

Adi Zitrin

Galaxy Cluster Abell 370 and its famous gravitational arcs, imaged with the Hubble Space Telescope.

Massive galaxy clusters bend light rays from background sources to form magnified, distorted, and multiple arcs. Using this Gravitational Lensing phenomenon, we can map the Dark Matter distribution of the lens, invisible otherwise. Thanks to the magnification power from lensing we can also access increasingly fainter and high-redshift (earlier) galaxies, and study the evolution of the first generation galaxies and the Reionization of the Universe.

Biological and Soft Matter Physics

Single Cell Dynamics

Mario Feingold

During the lifetime of a bacterium it elongates linearly in three distinct regimes.

We use single cell phase-contrast and fluorescence time-lapse microscopy to monitor morphological changes during the division of E. coli. To bypass the limitations of optical resolution, we process the images using pixel intensity values for edge detection. We study the dynamics of the constriction width, W, and find that its formation starts shortly after birth much earlier than can be detected by simply viewing phase-contrast images. A simple geometrical model is shown to reproduce the behavior of W(t). Moreover, the time-dependence of the cell length, L(t), consists of three linear regimes.

Condensed Matter Theory

Topological Supercoductors and Majorana Fermions

Eytan Grosfeld

Majorana fermion based superconducting qubit

We are interested in properties of topological superconductors, a fascinating state of matter that could be harnessed to create a new type of quantum computer [E. Ginossar and E. Grosfeld, Nature Communications 5, 4772 (2014), Tunability of microwave transitions as a signature of coherent parity mixing effects in the Majorana-transmon qubit.]

Atomic, Molecular and Optical Physics

Quantum Interferences and Lasing without inversion

Reuben Shuker

Sub-natural-width peak

Quantum-interference-related phenomena have many implications in physics. Quantum interference between two independent quantum channels in three-level systems gives rise to various coherent phenomena, such as electromagnetically induced transparency (EIT), coherent population trapping (CPT), lasing/gain without inversion (LWI/GWI), enhancement of refraction index, sub- and super-luminal light propagation etc. These phenomena open a wide-range perspective for new type of phase-sensitive spectroscopy. An example is the possibility to get sub-natural line widths (see movie).

Condensed Matter Experimental

Magnetic Resonance on the single atom level

Yishay Manassen

above-silicon surface with carbide spots below tunneling junction and spin - spectrum

In the STM image shown, observed in our lab, we see some disordered white spots. The STM does not have chemical identification capability. Such chemical identification is observed macroscopically using macroscopic magnetic resonance – both of electrons and nuclei. We develop a magnetic resonance technique on the single atom level, observed via a Larmor frequency component in the tunneling current. We identify the type of atoms under the tip using their spectrum – for example the SiC hyperfine spectrum. Preliminary results showed the observation of the nuclear transitions (NMR) with the STM.

High-Energy Physics

Fluid-Gravity Correspondence

Michael Lublinsky

Illustration of a collision of two gold nuclei at RHIC.

Quark Ggluon Plasma (QGP) is created in Heavy Ion Collisions at the Relativistic Heavy Ion Collider (RHIC) and LHC. A striking discovery of RHIC is that QGP produced there is strongly coupled and behaves like a nearly perfect fluid with relativistic hydrodynamics being an appropriate description of the observed phenomena. Remarkably, hydrodynamical properties of QGP could be studied using gravitational theory of Black Holes in curved five-dimensional spaces. The fluid/gravity correspondence relates graviton`s absorption by a Black Hole to dissipation taking place in the QGP.