Resonances in a periodically driven bosonic system

TL;DR

This paper investigates how periodic driving in a non-interacting bosonic system with unbounded energy levels leads to resonant stable states, shedding light on conditions that cause heating in quantum systems.

Contribution

It introduces a model of a non-interacting bosonic system with unbounded energy levels coupled resonantly by a periodic drive, exploring heating dynamics beyond previous studies.

Findings

Resonant stable states emerge due to stimulated emission and absorption.

Heating depends on the specific driving protocol used.

The study clarifies conditions under which resonant driving induces heating.

Abstract

Periodically driven systems are a common topic in modern physics. In optical lattices specifically, driving is at the origin of many interesting phenomena. However, energy is not conserved in driven systems, and under periodic driving, heating of a system is a real concern. In an effort to better understand this phenomenon, the heating of single-band systems has been studied, with a focus on disorder- and interaction-induced effects, such as many-body localisation. Nevertheless, driven systems occur in a much wider context than this, leaving room for further research. Here, we fill this gap by studying a non-interacting model, characterised by discrete, periodically spaced energy levels that are unbounded from above. We couple these energy levels resonantly through a periodic drive, and discuss the heating dynamics of this system as a function of the driving protocol. In this way, we show that a combination of stimulated emission and absorption causes the presence of resonant stable states. This will serve to elucidate the conditions under which resonant driving causes heating in quantum systems.