Domain wall skew scattering in ferromagnetic Weyl metals

TL;DR

This paper investigates how magnetic domain walls in ferromagnetic Weyl metals cause skew scattering that significantly affects Hall conductivity, highlighting the importance of beyond-linear models for accurate predictions.

Contribution

It reveals the impact of domain wall scattering on Hall effects in Weyl metals and shows that linearized models are insufficient, emphasizing the need for curvature terms in theoretical descriptions.

Findings

Strong skew scattering near Weyl points causes additional Hall effect.

Linearized models fail to capture domain wall physics accurately.

Including curvature terms improves agreement with lattice model results.

Abstract

We study transport in the presence of magnetic domain walls (DWs) in a lattice model of ferromagnetic type-I Weyl metals. We compute the diagonal and Hall conductivities in the presence of a DW, using both Kubo and Landauer formalisms, and uncover the effect of DW scattering. When the Fermi level lies near Weyl points, we find a strong skew scattering at the DW which leads to a significant additional Hall effect. We estimate the average Hall resistivity for multi-domain configurations and identify the limit where the DW scattering contribution becomes significant. We show that a continuum model obtained by linearizing the lattice dispersion around the Weyl points does not correctly capture this DW physics. Going beyond the linearized theory, and incorporating leading curvature terms, leads to a semi-quantitative agreement with our lattice model results. Our results are relevant for experiments on the Hall resistivity of spin-orbit coupled ferromagnets, which can have Weyl points near the Fermi energy.