Abstract:

A distinctive feature of atomic, molecular, and optical systems is that interactions between particles are often long-ranged. Control techniques from quantum optics often allow one to tune the pattern of these long-range interactions, creating an entirely new degree of freedom, absent in typical condensed matter systems. These tunable long-range interactions can result in very different far-from-equilibrium dynamics compared to systems with only short-range interactions. In the first half of the talk, I will describe how very general types of long-range interactions can qualitatively change the entanglement and correlation growth shortly after a quantum quench. In the second half of the talk I will show that, at longer times, long-range interactions can lead to exotic paths towards thermalization. These theoretical ideas have been explored in recent trapped-ion experiments, and connections to these experiments will be emphasized in both parts of the talk.

References:
(1) B. Neyenhuis, J. Smith, A. Lee, P. Richerme, P. Hess, J. Zhang, Z.-X. Gong, A. V. Gorshkov, and C. Monroe, arXiv:1608.00681 (2016; under review by Nature)
(2) P. Richerme, Z.-X. Gong, A. Lee, C. Senko, J. Smith, M. Foss-Feig, S. Michalakis, A. V. Gorshkov, and C. Monroe, Nature 511, 198 (2014)
(3) Z.-X. Gong, M. Foss-Feig, S. Michalakis, and A. V. Gorshkov, Phys. Rev. Lett. 113, 030602 (2014)
(4) M. Foss-Feig, Z.-X. Gong, C. W. Clark, and A. V. Gorshkov, Phys. Rev. Lett. 114, 157201 (2015) 

Short Bio:

Zhexuan Gong obtained his PhD in Physics from University of Michigan in 2013. He worked with Prof. Luming Duan during his PhD, focusing on the physical implementation of quantum computation and quantum simulation. Since graduation, he has been working at the Joint Quantum Institute as a postdoc and now as a research scientist. His current research interests involve a broad array of topics in quantum many-body physics, including quench dynamics, thermalization, topological order, and entanglement area law. He is particularly interested in long-range interacting systems and has a close collaboration with ion-trap experimentalists.