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

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 environmentwill necessarily thermalize the system and erase all signatures of MBL. This presents a challenge forexperimental investigations of MBL since no realistic system can ever be fully closed. In this work, weexperimentally explore the thermalization dynamics of a localized system in the presence of controlleddissipation. Specifically, we find that photon scattering results in a stretched exponential decay of an initialdensity pattern with a rate that depends linearly on the scattering rate. We find that the resultingsusceptibility increases significantly close to the phase transition point. In this regime, which is inaccessibleto current numerical studies, we also find a strong dependence on interactions. Our work provides a basisfor systematic studies of MBL in open systems and opens a route towards extrapolation of closed-systemproperties from experiments.