Ergodic-localized junctions in periodically-driven systems

TL;DR

This paper explores how coupling an ergodic and a localized domain in a periodically-driven spin chain affects their phases, revealing stability of localization under strong disorder and transition to ergodicity as disorder weakens.

Contribution

It introduces a combined graph and Floquet theoretical approach to analyze phase stability and transitions in driven quantum systems with mixed phases.

Findings

Localized domain remains stable under strong disorder.

Decreasing disorder causes the localized domain to become ergodic.

The study provides insights into phase stability in driven quantum systems.

Abstract

Quantum phases of matter have many relevant applications in quantum computation and quantum information processing. Current experimental feasibilities in diverse platforms allow us to couple two or more subsystems in different phases. In this letter, we investigate the situation where one couples two domains of a periodically-driven spin chain where one of them is ergodic while the other is fully localized. By combining tools of both graph and Floquet theory, we show that the localized domain remains stable for strong disorder, but as this disorder decreases the localized domain becomes ergodic.