Large intrinsic anomalous Hall effect in half-metallic ferromagnet Co3Sn2S2 with magnetic Weyl fermions

TL;DR

This paper reports a large intrinsic anomalous Hall effect in the half-metallic ferromagnet Co3Sn2S2, attributed to Weyl fermions near the Fermi energy, with the effect depending linearly on magnetization.

Contribution

It provides a combined theoretical and experimental analysis linking Weyl fermions to the intrinsic AHE in Co3Sn2S2, highlighting its topological origin.

Findings

Large intrinsic AHE observed in Co3Sn2S2

Intrinsic AHE originates from Weyl fermions near Fermi energy

AHE conductivity varies linearly with magnetization

Abstract

The origin of anomalous Hall effect (AHE) in magnetic materials is one of the most intriguing aspect in condensed matter physics and has been controversial for a long time. Recent studies indicate that the intrinsic AHE is closely related to the Berry curvature of occupied electronic states. In a magnetic Weyl semimetal with broken time-reversal symmetry, there are significant contributions on Berry curvature around Weyl nodes, which would lead to a large intrinsic AHE. Here, we report the large intrinsic AHE in the half-metallic ferromagnet Co3Sn2S2 single crystal. By systematically mapping out the electronic structure of Co3Sn2S2 theoretically and experimentally, the large intrinsic AHE should originate from the Weyl fermions near the Fermi energy. Furthermore, the intrinsic anomalous Hall conductivity depends linearly on the magnetization and this can be attributed to the sharp decrease of magnetization and the change of topological characteristics.