Daniel Podolsky
Krill Prize 2014
Technion
Ass.Prof. Daniel Podolsky (פופ”מ דניאל פודולסקי)
Research Interests:
Quantum mechanics of interacing electrons and atoms
My research spans a number of topics that are currently at the forefront of
condensed matter physics research. These include the theoretical exploration of the
Higgs mode in condensed matter and ultracold atomic systems, the proposal of
methods to induce topological properties by the use of light, and the study of
statistical mechanics systems out of equilibrium.
One of the main goals of condensed matter physics is to understand the collective
excitations that emerge from the interactions between the fundamental degrees of
freedom of a system. Recently, there has been broad interest in understanding the
Higgs mode, a collective excitation associated with oscillations in the amplitude of the
order parameter. This mode is a direct analogue of the Higgs particle of the Standard
Model, recently detected at the Large Hadron Collider. However, unlike the Higgs
particle, the Higgs mode in condensed matter makes its appearance at much lower
energies. It appears in a wide variety of systems, including superconductors, charge
density waves, magnets, and superfluids near the Mott transition. The Higgs mode
teaches us essential information about the dynamics underlying these systems.
In recent work with A. Auerbach and D. P. Arovas, I predicted that the Higgs mode is
a sharp excitation in two dimensional systems, and proposed a method for its
detection. This went against the common lore at the time, which held that the mode is
too short-lived to be meaningfully defined. Our prediction was confirmed within a few
months in experiments on cold bosonic gases, where the mode was clearly seen for
the first time in a two dimensional system. Following this success, I have been
studying various aspects of the Higgs mode, such as demonstrating that the mode
survives as a sharp excitation even when the system is close to being disordered at a
quantum phase transition, and studying its properties in antiferromagnets and
superconductors.
A second area of current research involves the study of light-induced topological
phases of matter. Topological insulators have attracted great interest in the
community due to their striking properties, such as conduction that occurs only at
their surfaces. Together with the group of M. Segev, I used the ideas predicted by the
theory of topological insulators to develop a photonic system with robust optical
waves that move in one direction, bypassing obstacles and imperfections that lie in
their way. In separate work together with my student Y. Tenenbaum Katan, I have
shown that light-induced topological phases can be manipulated in ways leading to
great potential for applications.
Finally, I am currently studying the statistical mechanics of out-of-equilibrium
systems. In an ongoing collaboration with G. Bunin and Y. Kafri, we are exploring the
large deviation function of systems that carry currents. A number of surprising
properties that are uniquely non-equilibrium arise in this case, such as long-range
correlations that are induced by the currents themselves. I am currently studying how
these effects manifest themselves in superconductors and in open quantum systems.