Quantum order at infinite temperature, time crystals, and dissipation

Speaker: Dr Achilleas Lazarides (Loughborough)

Discrete time crystals is the (contentious) name given to many-body systems displaying long-time dynamics that is sub-harmonic with respect to a driving frequency. While these were first discussed in closed quantum systems a few years ago, recent work (partly motivated by experiments) has focussed on including non-unitary effects such as due to an external environment ("dissipation").

In this talk I will begin by discussing general features of periodically-driven many-body systems, then concentrate on one of the unitary models for discrete time crystals. Finally I will discuss a general framework for subharmonic oscillations stabilised by dissipative dynamics.