Large topological Hall effect in a geometrically frustrated kagome magnet Fe$_3$Sn$_2$

TL;DR

This paper reports a large topological Hall effect in a kagome magnet Fe3Sn2, which varies with temperature and magnetic structure, indicating the presence of magnetic skyrmions and emergent phenomena in this geometrically frustrated system.

Contribution

It demonstrates the observation of a significant topological Hall effect in Fe3Sn2, linking it to magnetic skyrmions and topological spin textures in a kagome lattice for the first time.

Findings

Topological Hall resistivity reaches -0.875 μΩ·cm at 380 K.

The THE correlates with magnetic structure transformations.

Evidence suggests THE originates from topological magnetic spin textures.

Abstract

We report on the observation of a large topological Hall effect (THE) over a wide temperature region in a geometrically frustrated Fe3Sn2 magnet with a kagome-bilayer structure. We found that the magnitude of the THE resistivity increases with temperature and reaches -0.875 {\mu}{\Omega}.cm at 380 K. Moreover, the critical magnetic fields with the change of THE are consistent with the magnetic structure transformation, which indicates that the real-space fictitious magnetic field is proportional to the formation of magnetic skyrmions in Fe3Sn2. The results strongly suggest that the large THE originates from the topological magnetic spin textures and may open up further research opportunities in exploring emergent phenomena in kagome materials.