Periodically and quasiperiodically driven-anisotropic Dicke model

TL;DR

This paper investigates how periodic and quasiperiodic drives affect the anisotropic Dicke model, revealing phenomena like prethermal plateaus and modifications to quantum critical points, with implications for understanding driven quantum systems.

Contribution

It introduces a detailed analysis of drive-induced phenomena in the anisotropic Dicke model, highlighting differences between periodic and quasiperiodic driving effects.

Findings

Quasiperiodic drives induce a prethermal plateau increasing with frequency.

Periodic drives lead to a plateau without subsequent heating.

Plateau values depend on initial energy and Hamiltonian parameters.

Abstract

We analyze the anisotropic Dicke model in the presence of a periodic drive and under a quasiperiodic drive. The study of drive-induced phenomena in this experimentally accesible model is important since although it is simpler than full-fledged many-body quantum systems, it is still rich enough to exhibit many interesting features. We show that under a quasiperiodic Fibonacci (Thue-Morse) drive, the system features a prethermal plateau that increases as an exponential (stretched exponential) with the driving frequency before heating to an infinite-temperature state. In contrast, when the model is periodically driven, the dynamics reaches a plateau that is not followed by heating. In either case, the plateau value depends on the energy of the initial state and on the parameters of the undriven Hamiltonian. Surprisingly, this value does not always approach the infinite-temperature state monotonically as the frequency of the periodic drive decreases. We also show how the drive modifies the quantum critical point and discuss open questions associated with the analysis of level statistics at intermediate frequencies.