Interacting Fermi Gases in Disordered One-Dimensional Lattices

TL;DR

This paper investigates how disorder affects the phases of interacting Fermi gases in one-dimensional lattices, revealing that strong disorder destroys insulating regions and causes anomalies in compressibility at low densities.

Contribution

It provides a theoretical analysis of the impact of random potentials on ground-state phases of 1D Fermi gases using a density-functional approach.

Findings

Disorder destroys local insulating regions when sufficiently strong.

Disorder induces a compressibility anomaly at low density.

Percolation quenching affects the system's compressibility.

Abstract

Interacting two-component Fermi gases loaded in a one-dimensional (1D) lattice and subject to harmonic trapping exhibit intriguing compound phases in which fluid regions coexist with local Mott-insulator and/or band-insulator regions. Motivated by experiments on cold atoms inside disordered optical lattices, we present a theoretical study of the effects of a random potential on these ground-state phases. Within a density-functional scheme we show that disorder has two main effects: (i) it destroys the local insulating regions if it is sufficiently strong compared with the on-site atom-atom repulsion, and (ii) it induces an anomaly in the compressibility at low density from quenching of percolation.