Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, 100872, Beijing, China.
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.
Nat Commun. 2018 Sep 11;9(1):3681. doi: 10.1038/s41467-018-06088-2.
The origin of anomalous Hall effect (AHE) in magnetic materials is one of the most intriguing aspects in condensed matter physics and has been a controversial topic 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 to Berry curvature around Weyl nodes, possibly leading to a large intrinsic AHE. Here, we report the quite large AHE in the half-metallic ferromagnet CoSnS single crystal. By systematically mapping out the electronic structure of CoSnS both theoretically and experimentally, we demonstrate that the intrinsic AHE from the Weyl fermions near the Fermi energy is dominating. The intrinsic anomalous Hall conductivity depends linearly on the magnetization and can be reproduced by theoretical simulation, in which the Weyl nodes monotonically move with the constrained magnetic moment on Co atom.
反常霍尔效应（AHE）在磁性材料中的起源是凝聚态物理中最有趣的方面之一，长期以来一直是一个有争议的话题。最近的研究表明，本征 AHE 与占据电子态的 Berry 曲率密切相关。在具有破坏时间反转对称性的磁性 Weyl 半金属中，Weyl 节点周围的 Berry 曲率有很大的贡献，这可能导致很大的本征 AHE。在这里，我们报告了在半金属铁磁体 CoSnS 单晶中相当大的 AHE。通过系统地从理论和实验上描绘 CoSnS 的电子结构，我们证明了来自费米能级附近的 Weyl 费米子的本征 AHE 占主导地位。本征反常霍尔电导率与磁化强度呈线性关系，可以通过理论模拟再现，其中 Weyl 节点随 Co 原子上受约束的磁矩单调移动。
