Anomalous Hall effect by chiral spin textures in two-dimensional Luttinger model

TL;DR

This paper investigates how spin-orbit interactions influence the anomalous Hall effect caused by chiral spin textures in a two-dimensional Luttinger model, revealing suppression effects and new terms related to skyrmion helicity.

Contribution

It demonstrates the significant impact of crystal symmetry and spin-orbit interaction on the chirality-related anomalous Hall effect in centrosymmetric magnets, introducing a novel Hall conductivity term.

Findings

Anomalous Hall effect is suppressed by over an order of magnitude compared to quadratic dispersion.

Chiral Hall effect contributions vanish in the Rashba model.

A new term distinguishes Hall conductivity for Bloch and Neel skyrmions.

Abstract

Long-range magnetic textures, such as magnetic skyrmion, give rise to rich transport properties in magnetic metals, such as the anomalous Hall effect related to spin chirality, a.k.a. topological Hall effect. In addition to the topological Hall effect, recent studies on non-centrosymmetric magnets find that the spin-orbit interaction of itinerant electrons gives rise to novel contributions related to spin chirality, i.e., the chiral Hall effect. In this work, we discuss that the spin-orbit interaction has a distinct, yet significant, effect on the anomalous Hall effect related to spin chirality in centrosymmetric magnets. Using a scattering theory method, we find that the anomalous Hall effect related to scalar spin chirality in a two-dimensional Luttinger model is suppressed by more than one order of magnitude compared to the quadratic dispersion, and the contributions similar to the chiral Hall effect in Rashba model vanishes. At the same time, a novel term that gives different Hall conductivity for the Bloch and Neel skyrmions occurs, thereby enabling the detection of the skyrmion helicity. The striking differences demonstrate the rich effect of crystal symmetry on the chirality-related anomalous Hall effect in materials with strong spin-orbit interaction.