Two-dimensional conductors with interactions and disorder from particle-vortex duality

TL;DR

This paper explores how particle-vortex duality in 2D Dirac fermions coupled to gauge fields reveals new strongly interacting metallic states that can avoid localization, with implications for understanding 2D conductors.

Contribution

It introduces a duality-based framework for analyzing disordered 2D Dirac fermions, providing new examples of metals that resist Anderson localization.

Findings

Vortices of Dirac fermions can localize, leading to perfect conduction.

Finite vortex conductivity implies the original fermions are conducting.

The study offers new models of strongly interacting 2D metals.

Abstract

We study Dirac fermions in two spatial dimensions (2D) coupled to strongly fluctuating U(1) gauge fields in the presence of quenched disorder. Such systems are dual to theories of free Dirac fermions, which are vortices of the original theory. In analogy to superconductivity, when these fermionic vortices localize, the original system becomes a perfect conductor, and when the vortices possess a finite conductivity, the original fermions do as well. We provide several realizations of this principle and thereby introduce new examples of strongly interacting 2D metals that evade Anderson localization.