Condensed Matter Theory
*** Quantum mechanics of nanometer sized devices: using electron wave interference to manipulate electron motion. *** Spintronics: taking advantage of the electron’s magnetic moment (spin), and not only of its charge, to store and read information. Possible applications in quantum computers. *** Multiferroic materials are both magnetic and ferroelectric, and therefore can be manipulated by both electric and magnetic fields.
Biological and Soft Matter Physics
The front of a fluid that displaces a less viscous fluid in shear-dominated flows is known to be stable. We show that in predominantly extensional flows on a sphere, a similar front of a strain-rate-softening fluid can become unstable and evolve fingerlike patterns comprised of rifts and tongues. The number of rifts and tongues declines with time and is selected by competition between interfacial hoop stress, geometric stretching, momentum dissipation, and spatial curvature. Our results elucidate fracture dynamics in complex fluids under extension and are applicable to a wide range of systems, including planetary-scale ice shelves as in snowball epochs and icy moons.
Condensed Matter Experimental
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.
Astrophysics and Cosmology
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.
Are Einstein's equations and general relativity compatible with quantum mechanics? In spite of intense efforts over the last 40 years by some of the best physicists we still do not know the answer . I study the properties of black holes and other space-times with horizons to probe the laws of quantum gravity. Based on our recent research, our proposed answer is: Yes. The apparent incompatibilities between general relativity and quantum mechanics originate from the extreme approximation of treating spacetime as a strictly classical geometric object.
Atomic, Molecular and Optical Physics
We are setting up a brand-new research laboratory of Attosecond Science and Nanophotonics in the Physics Department of the Ben-Gurion University. In our group, we focus on both experimental and theoretical studies at the interface of ultrafast nonlinear optics, attosecond science and nanoscience. More specifically, our work involves generation, measurement and control of the interaction of light and matter in atoms, molecules and nanosystems in space and time at extremely short (attosecond=10^(-18)sec) time scales. Our interests range from fundamental physical phenomena to applications.