Speaker: Steve Campbell
Affiliation: University College Dublin
Date: Tuesday, 29 April 2025 at 12:00
Location: Online seminar
The emergence of time-periodic behaviour in quantum systems has been the focus of sustained interest in the last decade. Catalysed by Wilczek’s seminal works on the possibility for systems to be classified as “time-crystals”, alternative formulations have been proposed that are purported to exhibit a similar time-crystalline behaviour. In this talk, I will critically examine one such proposal, so-call “dissipative time crystals”, focusing on the onset and resilience of emergent time periodicity in a few-body all-to-all interacting Lipkin-Meshkov-Glick model, where one of the constituents is locally in contact with a thermal bath. Employing both a collision model framework and a suitable time-continuous description, we will discuss how stable time-periodic behavior can only be exhibited when the bath acts as a purely dissipative channel and we will assess the role that the microscopic interactions within the system play, establishing that for the all-to-all model the introduction of temperature leads to a melting of the emergent time periodicity, in contrast to stable long-time behavior which can be maintained for nearest neighbor XXZ type interactions. This talk will therefore also aim to provide a short introduction to collision models as a highly versatile tool for studying open quantum systems.