Metal-Insulator Transition in Disordered Two-Dimensional Electron Systems

TL;DR

This paper develops a theoretical framework for the metal-insulator transition in disordered two-dimensional electron systems, highlighting a quantum critical point influenced by electron interactions and disorder, which explains experimental observations.

Contribution

It introduces a theory identifying a quantum critical point driven by the interplay of interactions and disorder in 2D electron gases, explaining critical behavior near the transition.

Findings

Identification of a quantum critical point separating metallic and insulating phases

Divergence in the density of states at the transition

Explanation of anomalous spin susceptibility enhancement

Abstract

We present a theory of the metal-insulator transition in a disordered two-dimensional electron gas. A quantum critical point, separating the metallic phase which is stabilized by electronic interactions, from the insulating phase where disorder prevails over the electronic interactions, has been identified. The existence of the quantum critical point leads to a divergence in the density of states of the underlying collective modes at the transition, causing the thermodynamic properties to behave critically as the transition is approached. We show that the interplay of electron-electron interactions and disorder can explain the observed transport properties and the anomalous enhancement of the spin susceptibility near the metal-insulator transition.