Chiral phase transition in lattice QCD as a metal-insulator transition

TL;DR

This paper presents evidence that the chiral phase transition in lattice QCD is associated with a metal-insulator transition driven by Anderson localization of low-lying Dirac modes, impacting the understanding of QCD phase structure.

Contribution

It provides the first evidence linking the chiral transition in lattice QCD to a metal-insulator transition caused by Anderson localization.

Findings

Low lying Dirac modes undergo a transition at the chiral temperature.

Anderson localization appears to drive the transition to the chirally symmetric phase.

The localization phenomenon influences traditional phase transition models.

Abstract

We investigate the lattice QCD Dirac operator with staggered fermions at temperatures around the chiral phase transition. We present evidence of a metal-insulator transition in the low lying modes of the Dirac operator around the same temperature as the chiral phase transition. This strongly suggests the phenomenon of Anderson localization drives the QCD vacuum to the chirally symmetric phase in a way similar to a metal-insulator transition in a disordered conductor. We also discuss how Anderson localization affects the usual phenomenological treatment of phase transitions a la Ginzburg-Landau.