Many-body localization of 1D disordered impenetrable two-component fermions

TL;DR

This paper investigates how disorder affects the localization properties of 1D two-component fermions with strong interactions, revealing that potential disorder induces localization similar to Anderson localization, while magnetic disorder causes complex localization-delocalization transitions.

Contribution

It demonstrates the distinct effects of potential and magnetic disorder on many-body localization in strongly interacting 1D fermions, including reentrant transitions.

Findings

Potential disorder leads to Anderson localization at weak disorder.

Weak magnetic fields can destroy potential disorder-induced localization.

Strong magnetic fields can induce many-body localization.

Abstract

We study effects of disorder on eigenstates of 1D two-component fermions with infinitely strong Hubbard repulsion. We demonstrate that the spin-independent (potential) disorder reduces the problem to the one-particle Anderson localization taking place at arbitrarily weak disorder. In contrast, a random magnetic field can cause reentrant many-body localization-delocalization transitions. Surprisingly weak magnetic field destroys one-particle localization caused by not too strong potential disorder, whereas at much stronger fields the states are many-body localized. We present numerical support of these conclusions.