Conductivity of disordered quantum lattice models at infinite temperature: Many-body localization

TL;DR

This paper uses exact diagonalization to study the conductivity of disordered quantum lattice models at infinite temperature, providing evidence for many-body localization and estimating the critical disorder strength for the transition.

Contribution

It offers a reevaluation of conductivity behavior in disordered quantum systems, identifying a localized regime and estimating the transition point, contrasting recent studies.

Findings

Evidence of a localized regime at strong disorder

Estimated critical field for many-body localization transition

Comparison with recent related system investigations

Abstract

We reinvestigate the behavior of the conductivity of several disordered quantum lattice models at infinite temperature using exact diagonalization. Contrary to the conclusion drawn in a recent investigation of similar quantities in identical systems, we find evidence of a localized regime for strong random fields. We estimate the location of the critical field for the many-body localization transition for the random-field XXZ spin chain, and compare our findings with recent investigations in related systems.