### Israel Klich

*Ph.D., 2004, Israel Institute of Technology*

*Professor*

*Theoretical Condensed Matter Physics,Theoretical Mathematical Physics,Theoretical Quantum Information*

#### Research Interests

My main field of interest is condensed matter physics with strong overlaps with mathematical physics and field theory. My research interests include entanglement in many-body systems, the Casimir effect, topological order and non-equilibrium statistical mechanics.

__Entanglement in condensed matter and topological phases__. At low temperatures, a quantum description of matter is necessary. Such a description involves the almost unavoidable presence of non-classical correlations known as quantum entanglement. In the past decade, the role of entanglement in condensed matter and quantum information has been realized and is the driving force behind numerous recent developments. My work on this subject has been focused on the understanding the scaling of entanglement in many body states as well as finding possible experimental consequences of it.

Quantum correlations are also important for the understanding of topological phases. Such phases arise in certain lattice models and are conjectured to appear in fractional quantum Hall systems. It has been suggested that such systems may provide a robust way of performing quantum computations. I am interested in understanding these systems, and in particular, the transition between topological and non-topological states.

__Quantum electrodynamics and the Casimir effect__. The Casimir effect is a striking phenomenon in which mirrors experience a force due to zero point functions of the electromagnetic field. Variants of the effect appear in different areas of physics: from high-energy physics and cosmology to statistical mechanics and biophysics. The recent experimental demonstration of the effect has spurred active interest in the underlying theory as well as research into possible applications in Nano-technology. I have been working on various qualitative and quantitative aspects of this effect.

__Non-equilibrium__. While the above problems are mostly static, quantum fields that are subject to time-dependent classical constraints are also of great recent interest. Indeed, such systems are rapidly becoming an experiemental possibility in atomic and condensed matter systems. In this area, I have worked on such problems such as the theory of quantum quenches and coherent excitation of single particles from a fermion vacuum.

Finally, I am also interested in more "traditional" condensed matter problems, such as the properties of superconductors and magnetic materials.

#### Graduate Students

#### Selected Publications

D. Gioev and I. Klich, “Entanglement entropy of fermions in any dimension and the Widom conjecture,” Phys. Rev. Lett.** 96**, 100503 (2006)

O. Kenneth and I. Klich, “Opposites Attract - A Theorem About The Casimir Force,” Phys. Rev. Lett. **97** (2006) 160401

J. Keeling, I. Klich and L. S. Levitov, “Minimal excitation states of electrons in one-dimensional wires,” Phys. Rev. Lett. **97**, 116403 (2006)

I. Klich, C. Lannert, G. Refael, “Supercurrent survival under a Rosen-Zener quench of hard core bosons,” Phys. Rev. Lett. **99**, 205303 (2007)

I. Klich and L. S. Levitov, “Quantum Noise as an Entanglement Meter,”, Phys. Rev. Lett. **102**, 100502 (2009)

I Klich, “On the stability of topological phases on a lattice”, Annals of Physics, **325**, 10 (2010)