Tunable Anomalous Hall Effect in a Kagome Ferromagnetic Weyl Semimetal

TL;DR

This paper demonstrates that the anomalous Hall effect in a kagome ferromagnetic Weyl semimetal can be precisely tuned by the orientation of an applied magnetic field, revealing the role of spin switching and geometrical frustration.

Contribution

It shows that the AHE in Co_3Sn_2S_2 can be controlled by magnetic field orientation, highlighting the influence of local spin switching and kagome lattice frustration.

Findings

AHE can be tuned by magnetic field orientation within ~2 degrees of the kagome plane.

AHE vanishes when magnetic field is parallel to the kagome plane.

AHE decreases with magnetic fields collinear with the spin direction.

Abstract

Emerging from the intricate interplay of topology and magnetism, the giant anomalous Hall effect (AHE) is the most known topological property of the recently discovered kagome ferromagnetic Weyl semimetal Co_3Sn_2S_2 with the magnetic Co atoms arranged on a kagome lattice. Here we report that the AHE in Co_3Sn_2S_2 can be fine-tuned by an applied magnetic field orientated within ~2 degrees of the kagome plane, while beyond this regime, it stays unchanged. Particularly, it can vanish in magnetic fields parallel to the kagome plane and even decrease in magnetic fields collinear with the spin direction. This tunable AHE can be attributed to local spin switching enabled by the geometrical frustration of the magnetic kagome lattice, revealing that spins in a kagome ferromagnet change their switching behavior as the magnetic field approaches the kagome plane. Our results also suggest a versatile way to tune the properties of a kagome magnet.