[13a-S302-1~11] 10.1 新物質・新機能創成（作製・評価技術）

▼ [13a-S302-5] Colossal enhancement of spin-caloritronic unidirectional magnetoresistance in a Weyl ferromagnet at room temperature

〇(D)LIVIO LEIVA¹、Simon Granville²、Yao Zhang²、Sergey Dushenko³、Ei Shigematsu¹、Ryo Ohshima¹、Yuichiro Ando¹、Masashi Shiraishi¹ (1.Kyoto University、2.V. U. of Wellington、3.NIST)

キーワード：unidirectional magneto resistance, spin-caloritronics, anomalous nernst effect

Unidirectional magnetoresistance (UMR) is a novel spintronic feature in nano-science, which has been intensively studied in hopes of realizing all-electrical magnetization direction detection devices. However, cryogenic temperatures and/or high magnetic fields have been required to achieve noticeable effects. Here, we exploit the high heat-to-charge conversion efficiency of the Heusler alloy Weyl semimetal Co2MnGa to produce a two orders of magnitude enhancement of the room temperature UMR ratio, when compared with conventional ferromagnets. We reveal that Joule-heating-originated vertical thermal gradients, combined with the large anomalous Nernst effect in this topologically-non-trivial material, converge into the manifestation of a strong UMR in nano-scaled wires. Our results open up new horizons of using thermoelectric voltages in novel materials for magnetization direction detection.