Scaling theory of two-dimensional metal-insulator transitions

TL;DR

This paper analyzes the two-dimensional metal-insulator transition using scaling theory, revealing a symmetry in conductivity and resistivity and suggesting that disordered 2D metals are perfect metals but likely not Fermi liquids.

Contribution

It provides a scaling theory explanation for the 2D metal-insulator transition and uncovers a fundamental symmetry linking conductivity and resistivity.

Findings

Symmetry relating conductivity and resistivity observed.

Disordered 2D metals are perfect metals.

Most disordered 2D metals are likely not Fermi liquids.

Abstract

We discuss the recently discovered two-dimensional metal-insulator transition in zero magnetic field in the light of the scaling theory of localization. We demonstrate that the observed symmetry relating conductivity and resistivity follows directly from the quantum critical behavior associated with such a transition. In addition, we show that very general scaling considerations imply that any disordered two dimensional metal is a perfect metal, but most likely not a Fermi liquid.