Intrinsic Anomalous Hall Effect in Type-II Weyl Semimetals

TL;DR

This paper investigates the intrinsic anomalous Hall effect in type-II Weyl semimetals, revealing that tilting of the Weyl cones leads to non-universal Hall conductivity that can change sign and persist even with zero Weyl point separation.

Contribution

It provides a calculation of the anomalous Hall conductivity in type-II Weyl semimetals with tilted spectra, highlighting the non-universality and dependence on tilt parameters.

Findings

Hall conductivity can change sign with tilt parameters

Finite anomalous Hall effect can occur even with zero Weyl point separation

Tilted spectra induce non-universal Hall responses

Abstract

Recently, a new type of Weyl semimetal called type-II Weyl semimetal has been proposed. Unlike the usual (type-I) Weyl semimetal, which has a point-like Fermi surface, this new type of Weyl semimetal has a tilted conical spectrum around the Weyl point. Here we calculate the anomalous Hall conductivity of a Weyl semimetal with a tilted conical spectrum for a pair of Weyl points, using the Kubo formula. We find that the Hall conductivity is not universal and can change sign as a function of the parameters quantifying the tilts. Our results suggest that even for the case where the separation between the Weyl points vanishes, tilting of the conical spectrum could give rise to a finite anomalous Hall effect, if the tilts of the two cones are not identical.