Metal-insulator transition in spatially-correlated random magnetic field system

TL;DR

This paper investigates how spatial correlations in random magnetic fields induce a metal-insulator transition in two-dimensional electron systems, revealing a non-universal critical conductance and potential links to observed metallic phases.

Contribution

It demonstrates numerically that spatial correlations among random fluxes lead to a well-defined metal-insulator transition with a two-branch conductance scaling.

Findings

Identification of a metal-insulator transition driven by correlated magnetic disorder

Critical conductance around e^2/h with non-universality

Connection to experimentally observed two-dimensional metallic phases

Abstract

We reexamine the problem of delocalization of two-dimensional electrons in the presence of random magnetic field. By introducing spatial correlations among random fluxes, a well-defined metal-insulator transition characterized by a two-branch scaling of conductance has been demonstrated numerically. Critical conductance is found non-universal with a value around $e^2/h$. Interesting connections of this system with the recently observed B=0 two-dimensional metallic phase (Kravchenko et al., Phys. Rev. B {\bf 50}, 8039 (1994)) are also discussed.