Effective field theory of the disordered Weyl semimetal

TL;DR

This paper develops a field theory framework for disordered Weyl semimetals, revealing how topological effects and symmetry breaking influence electromagnetic responses and remain robust against disorder at large scales.

Contribution

It introduces a novel field theory approach capturing topological terms and their effects in disordered Weyl semimetals beyond perturbation theory.

Findings

Topological terms generate unconventional electromagnetic responses.

Chirality information persists despite disorder.

Field theory captures effects beyond diagrammatic methods.

Abstract

In disordered Weyl semimetals, mechanisms of topological origin lead to the protection against Anderson localization, and at the same time to different types of transverse electromagnetic response -- the anomalous Hall, and chiral magnetic effect. We here apply field theory methods to discuss the manifestation of these phenomena at length scales which are beyond the scope of diagrammatic perturbation theory. Specifically we show how an interplay of symmetry breaking and the chiral anomaly leads to a field theory containing two types of topological terms. Generating the unconventional response coefficients of the system, these terms remain largely unaffected by disorder, i.e. information on the chirality of the system remains visible even at large length scales.