Topological Hall effect enhanced at magnetic transition fields in a frustrated magnet EuCd$_2$

TL;DR

This study reveals a significant enhancement of the topological Hall effect at magnetic transition fields in EuCd$_2$, linked to complex spin textures at magnetic domain boundaries in a frustrated magnetic lattice.

Contribution

It demonstrates the first observation of a giant topological Hall effect driven by magnetic domain boundaries in a frustrated magnet EuCd$_2$, highlighting the role of non-trivial spin textures.

Findings

Multiple peak structures and hysteresis in Hall responses.

Sharp enhancement of THE at magnetic transition fields.

Possible formation of non-trivial spin textures at domain boundaries.

Abstract

Emergent magnetic fields exerted by topological spin textures of magnets lead to an additional Hall response of itinerant carriers called the topological Hall effect (THE). While THE as a bulk effect has been widely studied, THE driven by magnetic domain boundaries (DBs) has been elusive. Here, we report rich Hall responses characterized by multiple peak structures and a hysteresis loop in films of EuCd$_2$, where Eu layers form a geometrically frustrated lattice of Heisenberg spins. We uncover a THE component sharply enhanced at magnetic transition fields, indicating a giant contribution from non-trivial spin textures possibly formed at the DBs.