Anomalous Hall effect triggered by pressure-induced magnetic phase transition in α -Mn

• Published in: Physical review research Vol. 2; no. 4; p. 043090
• Main Authors: Akiba, Kazuto, Iwamoto, Kaisei, Sato, Takaaki, Araki, Shingo, Kobayashi, Tatsuo C.
• Format: Journal Article
• Language: English
• Published: American Physical Society 16.10.2020
• ISSN: 2643-1564; 2643-1564
• DOI: 10.1103/PhysRevResearch.2.043090

Recent interest in topological nature in condensed matter physics has revealed the essential role of Berry curvature in the anomalous Hall effect (AHE). However, since a large Hall response originating from Berry curvature has been reported in quite limited materials, the detailed mechanism remains unclear at present. Here, we report the discovery of a large AHE triggered by a pressure-induced magnetic phase transition in elemental α-Mn. The AHE is absent in the noncollinear antiferromagnetic phase at ambient pressure, whereas a large AHE is observed in the weak ferromagnetic phase under high pressure despite the small magnetization of ≈0.02μ_{B}/Mn. Our results indicate that the emergence of the AHE in α-Mn is governed by the symmetry of the underlying magnetic structure, providing a direct evidence of a switch between a zero and nonzero contribution of the Berry curvature across the phase boundary. α-Mn can be an elemental and tunable platform to reveal the role of Berry curvature in AHE.