Disorder Induced Ferromagnetism in Restricted Geometries

TL;DR

This paper investigates how on-site disorder affects the magnetic ground states of the infinite U Hubbard model, revealing no effect in 1D but an enhancement of spin polarization in 2D, with potential relevance to experimental systems.

Contribution

It demonstrates that disorder enhances ground state magnetism in two-dimensional Hubbard systems, contrasting with its negligible effect in one dimension.

Findings

Disorder has no influence on 1D systems' magnetism.

Disorder enhances spin polarization in 2D systems.

Relevance to experimental spin-polarized states in quantum dots and metallic grains.

Abstract

We study the influence of on-site disorder on the magnetic properties of the ground state of the infinite $U$ Hubbard model. We find that for one dimensional systems disorder has no influence, while for two dimensional systems disorder enhances the spin polarization of the system. The tendency of disorder to enhance magnetism in the ground state may be relevant to recent experimental observations of spin polarized ground states in quantum dots and small metallic grains.