Localization effects on magnetotransport of a disordered Weyl semimetal

TL;DR

This paper investigates how disorder and magnetic fields influence electron transport in Weyl semimetals, revealing enhanced localization of non-chiral modes under strong magnetic fields through an exact theoretical approach.

Contribution

It provides an exact analysis of localization effects in disordered Weyl semimetals, highlighting the magnetic field dependence of localization lengths using a non-linear sigma-model approach.

Findings

Localization length scales as 1/B in strong magnetic fields

Disorder mixes chiral and non-chiral modes affecting conductance

Exact distribution function of transmission probabilities derived

Abstract

We study magnetotransport in a disordered Weyl semimetal taking into account localization effects exactly. In the vicinity of a Weyl node, a single chiral Landau level coexists with a number of conventional non-chiral levels. Disorder scattering mixes these topologically different modes leading to peculiar localization effects. We derive the average conductance as well as the full distribution function of transmission probabilities along the field direction. Remarkably, we find that localization of the non-chiral modes is greatly enhanced in a strong magnetic field with the typical localization length scaling as $1/B$. Technically, we use the non-linear sigma-model formalism with a topological term describing the chiral states. The problem is solved exactly by mapping to an equivalent transfer matrix Hamiltonian.