Magnetic properties of interacting, disordered electron systems in d=2 dimensions

TL;DR

This study uses quantum Monte Carlo simulations to show that disorder can enhance ferromagnetic susceptibility in two-dimensional electron systems at low temperatures, independent of metal-insulator transitions.

Contribution

It provides the first detailed numerical evidence that disorder enhances ferromagnetic susceptibility in 2D interacting electron systems at low temperatures.

Findings

Disorder enhances ferromagnetic susceptibility at low temperatures.

The enhancement is not related to the metal-insulator transition.

The effect is a general property of disordered, interacting 2D electron systems.

Abstract

We compute the magnetic susceptibilities of interacting electrons in the presence of disorder on a two-dimensional square lattice by means of quantum Monte Carlo simulations. Clear evidence is found that at sufficiently low temperatures disorder can lead to an enhancement of the ferromagnetic susceptibility. We show that it is not related to the transition from a metal to an Anderson insulator in two dimensions, but is a rather general low temperature property of interacting, disordered electronic systems.