"Topological" Hall effect in the ferromagnetic microparticles with noncoplanar magnetization distribution

TL;DR

This paper develops a phenomenological theory for the topological Hall effect in ferromagnetic microparticles with noncoplanar magnetization, analyzing a vortex magnetization state and estimating the effect's magnitude.

Contribution

It introduces a new phenomenological framework for analyzing the topological Hall effect in particles with arbitrary magnetization distributions, focusing on vortex states.

Findings

The hysteresis loop of THE differs from the abnormal Hall effect.

The estimated THE magnitude in a 100 nm Co particle exceeds normal and abnormal Hall effects below 200 Oe.

The theory allows qualitative analysis of THE in complex magnetization configurations.

Abstract

The phenomenological theory for "topological" Hall effect (THE) is proposed. The theory can be used for qualitative analysis of THE in the medium with arbitrary magnetization distribution. In the paper the cylindrical particle with "vortex" magnetization is considered. The hysteresis loop of THE is qualitatively different comparing to abnormal Hall effect. The estimation of THE magnitude in the "vortex" particle is made. For Co particle with 100 nm diameter the THE exceeds normal and abnormal Hall effects until an external magnetic field less than 200 Oe.