電流による反強磁性体の超高速磁化スイッチングを 時間分解イメージング測定で可視化～ノンコリニア反強磁性体の100ピコ秒級の高速反転過程を解明～

2025-12-04 東京大学

高速電流パルスによる反強磁性体Mn₃Snの磁化制御の概念図

＜関連情報＞

• https://www.s.u-tokyo.ac.jp/ja/press/10998/
• https://www.nature.com/articles/s41563-025-02402-8

反強磁性ワイル半金属における非熱的電流誘起スイッチングの超高速時間分解観測 Ultrafast time-resolved observation of non-thermal current-induced switching in an antiferromagnetic Weyl semimetal

Kazuma Ogawa,Hanshen Tsai,Naotaka Yoshikawa,Takumi Matsuo,Yutaro Tsushima,Mihiro Asakura,Hanyi Peng,Takuya Matsuda,Tomoya Higo,Satoru Nakatsuji & Ryo Shimano
Nature Materials  Published:04 December 2025
DOI:https://doi.org/10.1038/s41563-025-02402-8

Abstract

Antiferromagnets have gained a growing interest for next-generation spintronic applications. Among them, the antiferromagnetic Weyl semimetal Mn₃Sn stands out because of its electrical and magnetic properties driven by its non-collinear spin structure at room temperature. Despite research progress on the current-induced switching of the magnetic octupole in Mn₃Sn, the ultrafast switching inherent to the antiferromagnet remains to be resolved, and the underlying mechanism is yet elusive. Here we measure the spatiotemporally resolved current-induced switching dynamics in polycrystalline Mn₃Sn films using ultrafast magneto-optical Kerr effect imaging, with current pulses as short as 140 ps. Our results directly reveal two distinct switching regimes depending on the intensity and duration of the current pulse: a non-thermal process that does not require the transient melting of antiferromagnetic order, and a temperature-assisted process that relies on heating above the magnetic ordering temperature. Our work highlights the potential of Mn₃Sn towards ultrafast magnetic recording devices.