2026-06-24 東京大学,高エネルギー加速器研究機構
交替磁性体では、スピンによって散乱された偏極中性子と、非磁性原子によって散乱された偏極中性子との干渉を利用することで、交替磁性ドメインを検出することができます。
＜関連情報＞
- https://www.issp.u-tokyo.ac.jp/maincontents/news2.html?pid=31294
- https://journals.aps.org/prl/abstract/10.1103/yklc-9n6t
偏極中性子回折によるバルクMnTeにおける異方性秩序スイッチングの観測 Observation of Altermagnetic Order Switching in Bulk MnTe by Polarized Neutron Diffraction
Zheyuan Liu, Shinichiro Asai, Shingo Takahashi, Hiraku Saito, Taro Nakajima, and Takatsugu Masuda
Physical Review Letters Published: 23 June, 2026
DOI: https://doi.org/10.1103/yklc-9n6t
Abstract
Altermagnetic order, characterized by the Néel vector, breaks time-reversal symmetry (TRS) even in the nonrelativistic limit. Although spin-polarized and anomalous transport phenomena emerge with this order, they are mutually compensated by TRS-connected antiphase domains with opposite Néel vectors. Here we employ polarized neutron diffraction to directly probe the altermagnetic order in MnTe. Pronounced nuclear-magnetic interference terms were observed, providing direct evidence of a net Néel vector in the bulk crystal. Moreover, a weak ferromagnetic moment (WFM), originating from relativistic spin-orbit coupling, was found to be coupled with the altermagnetic order. Both the altermagnetic order and the WFM can be switched by milli-Tesla-scale magnetic field cooling.
