Topological Hall-like behavior of multidomain ferromagnets

TL;DR

This paper demonstrates that non-monotonic Hall resistivity signals, often attributed to topological spin textures, can arise from domain wall effects in disordered ferromagnets without requiring chiral spin structures.

Contribution

It introduces a resistor network model showing how domain wall scattering can produce Hall-like signals, challenging the interpretation of topological Hall effects in experiments.

Findings

Non-monotonic Hall signals can originate from domain wall scattering.

The model reproduces Hall-like signals without chiral spin textures.

Careful analysis is needed to distinguish true topological effects.

Abstract

We investigate the emergence of topological Hall-like (THE-like) signals in disordered multidomain ferromagnets. Non-monotonic behavior in Hall resistivity, commonly attributed to topological spin textures such as skyrmions, is produced in a random resistor network model without any chirality. It arises from simple mechanisms of the anomalous Hall effect (AHE) in combination with the domain wall scattering. By varying domain configurations and domain wall resistances, we explore the conditions under which the non-monotonic resistivity can be enhanced. Our results emphasize the need for careful analysis in distinguishing between true topological Hall effects and artifacts caused by domain disorders.