Helicity-protected domain-wall magnetoresistance in ferromagnetic Weyl semimetal

TL;DR

This paper demonstrates a highly stable and large magnetoresistance effect in ferromagnetic Weyl semimetals' domain walls, protected by helicity mismatch, which remains robust despite disorder and wall thickness.

Contribution

It reveals a novel helicity-protected magnetoresistance in Weyl semimetals' domain walls, distinct from conventional effects, and discusses surface Fermi arc contributions.

Findings

Magnetoresistance remains nearly 100% in thick, disordered domain walls.

The effect is due to helicity mismatch of Weyl fermions.

Surface Fermi arcs influence the magnetoresistance.

Abstract

The magnetotransport properties of disordered ferromagnetic Weyl semimetals are investigated numerically. We found an extraordinarily stable and huge magnetoresistance effect in domain walls of Weyl semimetals. This effect originates from the helicity mismatch of Weyl fermions and is a specific property of Weyl semimetals. Although conventional magnetoresistance effects are strongly suppressed in domain walls where local magnetization varies gradually, the helicity-protected magnetoresistance in Weyl semimetals maintains almost $100\%$ of the magnetoresistance ratio for any kind of thick domain walls, even in the presence of disorder. The contribution of surface Fermi arcs to the magnetoresistance is also discussed.