Topological Hall effect and Berry phase in magnetic nanostructures

TL;DR

This paper explores the topological Hall effect in 2D magnetic nanostructures, showing it arises from Berry phase effects without spin-orbit coupling, and proposes an experiment to observe this phenomenon.

Contribution

It introduces a method to observe the topological Hall effect in magnetic nanostructures through a proposed experimental setup, highlighting a mechanism independent of spin-orbit coupling.

Findings

Predicted unambiguous observation of THE in nanostructures

Demonstrated THE arises solely from Berry phase effects

Proposed experimental parameters for detection

Abstract

We discuss the anomalous Hall effect in a two-dimensional electron gas subject to a spatially varying magnetization. This topological Hall effect (THE) does not require any spin-orbit coupling, and arises solely from Berry phase acquired by an electron moving in a smoothly varying magnetization. We propose an experiment with a structure containing 2D electrons or holes of diluted magnetic semiconductor subject to the stray field of a lattice of magnetic nanocylinders. The striking behavior predicted for such a system (of which all relevant parameters are well known) allows to observe unambiguously the THE and to distinguish it from other mechanisms.