Critical exponents at the unconventional disorder-driven transition in a Weyl semimetal

TL;DR

This paper calculates the critical exponents of a disorder-driven transition in Weyl semimetals using a two-loop renormalisation-group method, clarifying previous debates on their values.

Contribution

It provides an independent two-loop RG calculation of critical exponents for Weyl fermions, resolving existing controversies.

Findings

Critical exponents are calculated using a two-loop RG approach.

The results clarify discrepancies in the literature.

The study enhances understanding of disorder-driven transitions in Weyl semimetals.

Abstract

Disordered non-interacting systems in sufficiently high dimensions have been predicted to display a non-Anderson disorder-driven transition that manifests itself in the critical behaviour of the density of states and other physical observables. Recently the critical properties of this transition have been extensively studied for the specific case of Weyl semimetals by means of numerical and renormalisation-group approaches. Despite this, the values of the critical exponents at such a transition in a Weyl semimetal are currently under debate. We present an independent calculation of the critical exponents using a two-loop renormalisation-group approach for Weyl fermions in $2-\varepsilon$ dimensions and resolve controversies currently existing in the literature.