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arXiv · 2605.21616

Observation of Altermagnetic Order Switching in Bulk MnTe by Polarized Neutron Diffraction

Zheyuan Liu·Shinichiro Asai·Shingo Takahashi·Hiraku Saito·Taro Nakajima·Takatsugu Masuda
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Abstract

Altermagnetic order, characterized by the N\'{e}el 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 N\'{e}el 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 N\'{e}el 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.

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Zheyuan Liu, Shinichiro Asai, Shingo Takahashi, Hiraku Saito, Taro Nakajima, Takatsugu Masuda. 2026-05-20. Observation of Altermagnetic Order Switching in Bulk MnTe by Polarized Neutron Diffraction. https://arxiv.org/abs/2605.21616

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