Spin Spiral and Topological Hall Effect in a Metamagnet Fe$_{3}$Ga$_{4}$

TL;DR

This paper demonstrates that the thermal-fluctuation driven Topological Hall Effect mechanism, previously proposed for YMn6Sn6, also applies to Fe3Ga4, indicating its universality in itinerant spiral magnets.

Contribution

The study shows that the proposed THE mechanism explains experimental observations in Fe3Ga4, extending its applicability beyond YMn6Sn6.

Findings

Theoretical model matches experimental data for Fe3Ga4.

The mechanism is likely universal in similar magnetic materials.

THE may have been observed but overlooked in other compounds.

Abstract

A new mechanism for Topological Hall Effect (THE) was recently proposed for the spiral magnet YMn$_{6}$Sn$_{6},$ which requires transverse conical spiral (TCS) magnetism, induced by external magnetic field, combined with thermally excite helical spiral magnons. In principle, this mechanism should be applicable to other itinerant spiral magnets as well. In this paper, we show that another metamagnetic compound, Fe$_{3}$Ga$_{4}$, where THE was observed experimentally before, in one of its phases satisfies this condition, and the proposed theory of thermal-fluctuation driven THE is quantitatively consistent with the experiment. This finding suggests that this mechanism is indeed rather universal, and the effect may have been observed in other compounds before, but overlooked.