Periodic steady state and interference in a periodically driven quantum system

TL;DR

This paper investigates the dynamics of a periodically driven quantum many-body system, revealing that quantum coherence and interference lead to persistent time-periodic averages and prevent thermalization to infinite temperature.

Contribution

It demonstrates that destructive interference causes quantum averages to become periodic and shows Floquet resonance effects in a driven quantum Ising chain, extending insights to non-integrable systems.

Findings

Quantum averages become time-periodic due to destructive interference.

The system avoids reaching an infinite temperature state.

Resonance peaks and dips are observed in frequency-dependent observables.

Abstract

We study the coherent dynamics of a quantum many-body system subject to a time-periodic driving. We argue that in many cases, destructive interference in time makes most of the quantum averages time-periodic, after an initial transient. We discuss in detail the case of a quantum Ising chain periodically driven across the critical point, finding that, as a result of quantum coherence, the system never reaches an infinite temperature state. Floquet resonance effects are moreover observed in the frequency dependence of the various observables, which display a sequence of well-defined peaks or dips. Extensions to non-integrable systems are discussed.