Transition to an Insulating Phase Induced by Attractive Interactions in the Disordered Three-Dimensional Hubbard Model

TL;DR

This paper investigates how attractive interactions induce an insulating phase in a disordered three-dimensional Hubbard model, revealing a transition from superconducting to localized pair states within the metallic regime.

Contribution

It provides numerical evidence of a disorder-induced insulator transition driven by attractive interactions in a 3D Hubbard model, expanding understanding of phase transitions in disordered quantum systems.

Findings

Increasing attraction causes a transition from superconducting to insulating states.

The transition occurs within the metallic phase of the Anderson model.

Numerical simulations confirm the interplay of disorder and attraction affects localization.

Abstract

We study numerically the interplay of disorder and attractive interactions for spin-1/2 fermions in the three-dimensional Hubbard model. The results obtained by projector quantum Monte Carlo simulations show that at moderate disorder, increasing the attractive interaction leads to a transition from delocalized superconducting states to the insulating phase of localized pairs. This transition takes place well within the metallic phase of the single-particle Anderson model.