2025-09-03 東京科学大学
図1．従来の非磁性材料における正常ホール効果（左）・磁性材料における異常ホール効果（中央）と、面内磁場によって新たに明らかになった非磁性材料における異常ホール効果（右）。
＜関連情報＞
- https://www.isct.ac.jp/ja/news/acm3o7b752wn
- https://www.isct.ac.jp/plugins/cms/component_download_file.php?type=2&pageId=&contentsId=1&contentsDataId=2126&prevId=&key=5f957796a27b9d0dae0d42d382564e98.pdf
- https://journals.aps.org/prl/abstract/10.1103/5d7l-mr7k
面内磁場によるディラック半金属Cd₃As₂の異常ホール効果の観測 Anomalous Hall Effect in the Dirac Semimetal Cd3As2 Probed by In-Plane Magnetic Field
Shinichi Nishihaya, Hiroaki Ishizuka, Yuki Deguchi, Ayano Nakamura, Tadashi Yoneda, Hsiang Lee, Markus Kriener, and Masaki Uchida
Physical Review Letters Published: 2 September, 2025
DOI: https://doi.org/10.1103/5d7l-mr7k
Abstract
Intrinsic anomalous Hall effect (AHE) formulated by geometric properties of Bloch wave functions is a ubiquitous transport phenomenon not limited to magnetic systems but also allowed in nonmagnetic ones under an external field breaking time-reversal symmetry. On the other hand, detection of field-induced AHE is practically challenging because the band modulation through the Zeeman and spin-orbit couplings is typically small compared to other contributions as induced by the Lorentz force. Here, we demonstrate on Dirac semimetal Cd3As2 films that the field-induced AHE in nonmagnetic systems can be quantitatively probed by applying and rotating the magnetic field within the Hall deflection plane. Measurements on the Cd3As2 (112) plane reveal that AHE emerges as a clear threefold symmetric component for the in-plane field rotation. This intrinsic response becomes more pronounced in ultralow-electron-density films where significant variations in the geometric properties are expected under the magnetic field. Our findings open new opportunities in the research of Hall responses manifested as orbital magnetization in nonmagnetic systems.
