Effects of auto-correlated disorder on the dynamics in the vicinity of the many-body localization transition

TL;DR

This study investigates how auto-correlated disorder influences the transition between ergodic and localized phases in a many-body quantum system, revealing that correlations can suppress localization and alter dynamical properties.

Contribution

It provides a numerical analysis of the impact of auto-correlated disorder on many-body localization, highlighting how correlations modify static and dynamic behaviors.

Findings

Strong correlations suppress many-body localization.

Level repulsion is reduced at small disorder strengths.

Auto-correlated disorder affects time evolution of observables.

Abstract

The presence of frozen uncorrelated random on-site potential in interacting quantum systems can induce a transition from an ergodic phase to a localized one, the so-called many-body localization. Here we numerically study the effects of auto-correlated disorder on the static and dynamical properties of a one-dimensional many-body quantum system which exhibits many-body localization. Specifically, by means of some standard measures of energy level repulsion and localization of energy eigenstates, we show that a strong degree of correlations between the on-site potentials in the one-dimensional spin-1/2 Heisenberg model leads to suppression of the many-body localization phase, while level repulsion is mitigated for small disorder strengths, although energy eigenstates remain well extended. Our findings are also remarkably manifested in time domain, on which we put main emphasis, as shown by the time evolution of experimentally relevant observables, like the return probability and the spin auto-correlation function.