Observation of ergodicity breaking and quantum many-body scars in spinor gases

TL;DR

This paper demonstrates that spinor gases can exhibit ergodicity breaking and quantum many-body scars, with specific initial states remaining nonthermal under weak driving, providing insights into quantum dynamics and potential quantum information applications.

Contribution

It provides experimental and theoretical evidence of quantum many-body scars in spinor gases and explores the transition from integrability to thermalization with increasing driving strength.

Findings

Observation of nonthermal states indicating QMBS

Transition from integrable to thermal behavior with driving strength

Theoretical spectra support experimental results

Abstract

We experimentally and theoretically demonstrate spinor gases driven by spin-flopping fields are excellent platforms for investigating ergodicity breaking and quantum scarring. We observe that specific initial states remain nonthermal at weak driving despite the majority of states thermalizing, which constitutes clear evidence of quantum many-body scars (QMBS). As the driving strength increases, the experimental system undergoes a smooth transition from integrable to weakly ergodicity breaking, which supports QMBS, and then to fully thermal. This is in agreement with the theoretical spectra, which predict towers of states dissolving with increasing driving strength. This work advances the study of QMBS and quantum scars with applications to, e.g., quantum information storage.