Fate of many-body localization under periodic driving

TL;DR

This paper investigates how periodic driving affects many-body localized systems, revealing that a mobility edge causes delocalization at any driving strength, while fully localized systems delocalize only below a critical frequency.

Contribution

It demonstrates the critical role of a mobility edge in driving-induced delocalization and identifies a finite-frequency transition in fully localized systems.

Findings

Presence of a mobility edge leads to delocalization at any driving strength.

Fully localized systems delocalize only below a certain driving frequency.

Numerical studies on bosonic systems and quantum random energy model support these results.

Abstract

We study many-body localised quantum systems subject to periodic driving. We find that the presence of a mobility edge anywhere in the spectrum is enough to lead to delocalisation for any driving strength and frequency. By contrast, for a fully localised many-body system, a delocalisation transition occurs at a finite driving frequency. We present numerical studies on a system of interacting one-dimensional bosons and the quantum random energy model, as well as simple physical pictures accounting for those results.