Annealed disorder, rare regions, and local moments: A novel mechanism for metal-insulator transitions

TL;DR

This paper introduces a novel mechanism for metal-insulator transitions driven by annealed magnetic disorder, which affects the thermodynamic density susceptibility rather than localization, revealing a new universality class.

Contribution

It demonstrates that annealed magnetic disorder induces a new universality class for metal-insulator transitions in noninteracting electron systems at zero temperature.

Findings

Transition driven by vanishing density susceptibility

Critical behavior characterized near two dimensions

Proposes a new universality class for the transition

Abstract

Local magnetic moments in disordered sytems can be described in terms of annealed magnetic disorder, in addition to the underlying quenched disorder. It is shown that for noninteracting electron systems at zero temperature, the annealed disorder leads to a new mechanism, and a new universality class, for a metal-insulator transition. The transition is driven by a vanishing of the thermodynamic density susceptibility rather than by localization effects. The critical behavior near two-dimensions is determined, and the underlying physics is discussed.