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QI: Fachverband Quanteninformation

QI 37: Quantum Many Body Systems

QI 37.1: Talk

Friday, March 10, 2023, 14:30–14:45, F428

Metastable discrete time-crystal resonances in a dissipative central spin system — •Albert Cabot¹, Federico Carollo¹, and Igor Lesanovsky^1,2 — ¹Institut für Theoretische Physik, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany — ²School of Physics and Astronomy and Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom

We consider [1] the non-equilibrium behavior of a central spin system where the central spin is periodically reset to its ground state. The quantum mechanical evolution under this effectively dissipative dynamics is described by a discrete-time quantum map. Despite its simplicity this problem shows surprisingly complex dynamical features. In particular, we identify several metastable time-crystal resonances. Here the system does not relax rapidly to a stationary state but undergoes long-lived oscillations with a period that is an integer multiple of the reset period. At these resonances the evolution becomes restricted to a low-dimensional state space within which the system undergoes a periodic motion. Generalizing the theory of metastability in open quantum systems, we develop an effective description for the evolution within this long-lived metastable subspace and show that in the long-time limit a non-equilibrium stationary state is approached. Our study links to timely questions concerning emergent collective behavior in the "prethermal" stage of a dissipative quantum many-body evolution as well as to the phenomenon of quantum synchronization. [1] A. Cabot et al., Phys. Rev. B 106, 134311 (2022)