Anomaly related transport of Weyl fermions for Weyl semi-metals

TL;DR

This paper develops a quantum field theoretical model to analyze anomalous transport phenomena, like the chiral magnetic and vortical effects, in Weyl semi-metals, aligning with kinetic theory results and suggesting experimental tests.

Contribution

It introduces a field theoretical framework for anomalous transport in Weyl semi-metals, clarifying the nature of covariant currents and their relation to observable effects.

Findings

CME and CVE calculated in various currents

Results match kinetic theory analyses

Proposes experimental tests sensitive to temperature and gravitational effects

Abstract

We present a field theoretical model of anomalous transport in Weyl semi-metals. We calculate the Chiral Magnetic and Chiral Vortical Effect in the electric, axial (valley) and energy current. Our findings coincide with the results of a recent analysis using kinetic theory in the bulk of the material. We point out that the kinetic currents have to be identified with the covariant currents in quantum field theory. These currents are anomalous and the CME appears as anomalous charge creation/annihilation at the edges of the Weyl semi-metal. We discuss a possible simultaneous experimental test of the chiral magnetic and the chiral vortical effect sensitive to the temperature dependence induce by the gravitational contribution to the axial anomaly.