Zoom link: https://princeton.zoom.us/j/94074317938

Abstract: 

Recent progress in the realm of noisy, intermediate scale quantum (NISQ) devices opens exciting opportunities for many-body physics, in the form of new laboratory platforms with unprecedented control and measurement capabilities. It is natural to ask which kinds of new phenomena may be realized and observed by leveraging these capabilities. In this talk I will focus on a paradigmatic example: discrete time crystals (DTCs), novel non-equilibrium states of matter that break time translation symmetry and are possible only in driven, disordered systems. I will review the theory of DTCs and the results of past experiments (on platforms ranging from trapped ions to solids), in which transient ('prethermal') cousins of the DTC were realized. These experiments help formulate a checklist of requirements for the observation of a fully-fledged, stable incarnation of this phase. The requirements turn out to be a remarkably close match for a new generation of digital quantum simulators, such as Google's Sycamore processor, which can be programmed to realize the DTC phase and to experimentally detect its signature spatiotemporal order. Finally I will discuss the effects of environmental decoherence, and how they can be distinguished from "internal decoherence" coming from closed-system thermalization dynamics.

Reference: MI, K. Kechedzhi, R. Moessner, S. L. Sondhi and V. Khemani, arXiv:2007.11602 (2020).