Anderson-localization versus delocalization of interacting fermions in one dimension

TL;DR

This study uses the density matrix renormalization group to analyze how strong interactions and disorder affect localization in one-dimensional spinless fermions, revealing a delocalized phase with attractive interactions.

Contribution

It provides high-accuracy analysis of phase sensitivity in disordered interacting fermions and identifies a finite delocalized phase for attractive interactions.

Findings

Phase sensitivity distribution is log-normal.

Fluctuations grow algebraically with system size (~2/3 exponent).

Delocalized phase exists for attractive interactions.

Abstract

Using the density matrix renormalization group algorithm, we investigate the lattice model for spinless fermions in one dimension in the presence of a strong interaction and disorder. The phase sensitivity of the ground state energy is determined with high accuracy for systems up to a size of 60 lattice constants. This quantity is found to be log-normally distributed. The fluctuations grow algebraically with system size with a universal exponent of ~2/3 in the localized region of the phase diagram. Surprizingly, we find, for an attractive interaction, a delocalized phase of finite extension. The boundary of this delocalized phase is determined.