Chiral pair of Fermi arcs, anomaly cancelation, and spin or valley Hall effects in inversion symmetry-broken Weyl metals

TL;DR

This paper demonstrates how anomaly cancelation in inversion symmetry-broken Weyl metals leads to the formation of chiral Fermi arc pairs, which give rise to quantized spin or valley Hall effects, extending previous understanding from time-reversal symmetry-broken cases.

Contribution

It provides a minimal model explicitly showing anomaly cancelation in inversion symmetry-broken Weyl metals and explains the emergence of chiral Fermi arc pairs and their associated quantized Hall effects.

Findings

Explicit demonstration of anomaly cancelation in inversion symmetry-broken Weyl metals.

Identification of chiral Fermi arc pairs in these materials.

Prediction of quantized spin and valley Hall effects.

Abstract

Anomaly cancelation has been shown to occur in time-reversal symmetry-broken Weyl metals, which explains the existence of a Fermi arc. We extend this result in the case of inversion symmetry-broken Weyl metals. Constructing a minimal model that takes a double pair of Weyl points, we demonstrate the anomaly cancelation explicitly. This demonstration explains why a chiral pair of Fermi arcs appear in inversion symmetry-broken Weyl metals. In particular, we find that this pair of Fermi arcs gives rise to either "quantized" spin Hall or valley Hall effects, which corresponds to the "quantized" version of the charge Hall effect in time-reversal symmetry-broken Weyl metals.