Signatures of Many-Body Localization in a Controlled Open Quantum System

TL;DR

This study investigates how many-body localized quantum systems behave under controlled dissipation, revealing decay dynamics and phase transition effects, and providing insights for experimental exploration of MBL in realistic open systems.

Contribution

It demonstrates the effects of controlled dissipation on MBL systems, showing how photon scattering influences thermalization and phase transition behavior.

Findings

Photon scattering causes stretched exponential decay of density patterns.

Susceptibility increases near the MBL phase transition.

Strong interaction dependence observed in the transition regime.

Abstract

In the presence of disorder, an interacting closed quantum system can undergo many-body localization (MBL) and fail to thermalize. However, over long times even weak couplings to any thermal environment will necessarily thermalize the system and erase all signatures of MBL. This presents a challenge for experimental investigations of MBL, since no realistic system can ever be fully closed. In this work, we experimentally explore the thermalization dynamics of a localized system in the presence of controlled dissipation. Specifically, we find that photon scattering results in a stretched exponential decay of an initial density pattern with a rate that depends linearly on the scattering rate. We find that the resulting susceptibility increases significantly close to the phase transition point. In this regime, which is inaccessible to current numerical studies, we also find a strong dependence on interactions. Our work provides a basis for systematic studies of MBL in open systems and opens a route towards extrapolation of closed system properties from experiments.