2022年第83回応用物理学会秋季学術講演会

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10 スピントロニクス・マグネティクス » 10.4 半導体・トポロジカル・超伝導・強相関スピントロニクス

[23a-B201-1~12] 10.4 半導体・トポロジカル・超伝導・強相関スピントロニクス

2022年9月23日(金) 09:00 〜 12:15 B201 (B201)

永沼 博(東北大)、植本 光治(神戸大)

11:00 〜 11:15

[23a-B201-8] Observation of spin polarization of Weyl semimetal, WTe2, at room temperature

〇(M2)Kosuke Ohnishi1、Motomi Aoki1、Ei Shigematsu1、Ryo Ohshima1、Yuichiro Ando1,2、Taishi Takenobu3、Masashi Shiraishi1 (1.Kyoto Univ.、2.PRESTO, JST、3.Nagoya Univ.)

キーワード:Weyl semimetal, WTe2, Perpendicular magnetic anisotropy

A type-II Weyl semimetal, WTe2 is receiving great attention in spin physics because of the generation of spin polarization due to fictitious Weyl monopoles. In previous study, in-plane spin polarization originating from the Weyl node was reported by introducing an electrical method even though detection is limited at very low temperature. Meanwhile, the existence of perpendicularly spin polarization (Sz spin polarization) due to local symmetry breaking was suggested, and we attempted to observe Sz spin polarization using an all-electrical method.
Perpendicular magnetic anisotropy (PMA) electrodes and nonmagnetic Pt electrodes were deposited on the mechanically exfoliated WTe2, and the out-of-plane magnetic field dependence of spin voltages was measured from 5 K to 300 K. As a result, a clear hysteresis attributed to spin accumulation beneath the PMA electrode was observed up to 300 K. A detailed origin of the hysteresis and its supporting evidence will be given in the presentation.