Evolution of nodal line induced out-of-plane anomalous Hall effect in Co3Sn2S2

Abstract

Weyl semimetals have attracted considerable research interest over the past decade, with a number of intriguing transport phenomena reported. Magnetic Weyl semimetals, which break time reversal symmetry, have been predicted and recently discovered. Co3Sn2S2 is a magnetic Weyl semimetal that exhibit a giant anomalous Hall effect (AHE) when the magnetic moments are aligned along the c axis. In this paper, we report the evolution of the AHE with an external magnetic field applied in the ab plane and current along the c axis, namely, the out-of-plane AHE of Co3Sn2S2. Density functional theory calculations predict a finite out-of-plane AHE when the spins are fully aligned in the ab plane. The evolution of the magnetic structure modifies the nodal line distribution and the Berry curvature, resulting in a weaker AHE with an amplitude of 200Scm−1 at the saturation field. To ensure the alignment of the magnetic field in the ab plane, a two-round scanning process was performed experimentally. After this, the out-of-plane AHE was measured at multiple temperatures. The observed AHE signals with applied fields of 1 and 2 T were in good agreement with theoretical predictions. These results suggest that engineering the anomalous Hall effect may be possible by designing the symmetry relation of the local Berry curvature. Published by the American Physical Society 2025