Hall effect of spin-chirality origin in a triangular-lattice helimagnet Fe1.3Sb

TL;DR

This study demonstrates a topological Hall effect in a quasi-two-dimensional helimagnet Fe$_{1+x}$Sb, attributed to scalar spin chirality from heptamer spin-clusters influenced by Dzyaloshinsky-Moriya interaction.

Contribution

It reveals a novel topological Hall effect driven by spin chirality in a triangular-lattice helimagnet, highlighting the role of interstitial Fe and Dzyaloshinsky-Moriya interaction.

Findings

Observation of unconventional Hall resistivity with opposite sign to anomalous Hall effect

At low temperatures, spin freezing on interstitial Fe influences Hall response

Scalar spin chirality from heptamer spin-clusters explains the topological Hall effect

Abstract

We report on a topological Hall effect possibly induced by scalar spin chirality in a quasi-two- dimensional helimagnet Fe$_{1+x}$Sb. In the low-temperature region where the spins on interstitial- Fe (concentration $x=0.3$) intervening the $120^\circ$ spin-ordered triangular planes tend to freeze, a non-trivial component of Hall resistivity with opposite sign of the conventional anomalous Hall term is observed under magnetic field applied perpendicular to the triangular-lattice plane. The observed unconventional Hall effect is ascribed to the scalar spin chirality arising from the heptamer spin-clusters around the interstitial-Fe sites, which can be induced by the spin modulation by the Dzyaloshinsky-Moriya interaction.