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セガワ コウジ
SEGAWA KOJI
瀬川 耕司 所属 京都産業大学 理学部 物理科学科 職種 教授 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2016/08 |
| 形態種別 | 研究論文 |
| 標題 | Switching of charge-current-induced spin polarization in the topological insulator BiSbTeSe2 |
| 執筆形態 | その他 |
| 掲載誌名 | PHYSICAL REVIEW B |
| 出版社・発行元 | AMER PHYSICAL SOC |
| 巻・号・頁 | 94(7) |
| 著者・共著者 | Fan Yang,Subhamoy Ghatak,A. A. Taskin,Kouji Segawa,Yuichiro Ando,Masashi Shiraishi,Yasushi Kanai,Kazuhiko Matsumoto,Achim Rosch,Yoichi Ando |
| 概要 | The charge-current-induced spin polarization is a key property of topological insulators for their applications in spintronics. However, topological surface states are expected to give rise to only one type of spin polarization for a given current direction, which has been a limiting factor for spin manipulations. Here, we report that in devices based on the bulk-insulating topological insulator BiSbTeSe2, an unexpected switching of spin polarization was observed upon changing the chemical potential. The spin polarization expected from the topological surface states was detected in a heavily electron-doped device, whereas the opposite polarization was reproducibly observed in devices with low carrier densities. We propose that the latter type of spin polarization stems from topologically trivial two-dimensional states with a large Rashba spin splitting, which are caused by a strong band bending at the surface of BiSbTeSe2 beneath the ferromagnetic electrode used as a spin detector. This finding paves the way for realizing the "spin transistor" operation in future topological spintronic devices. |
| DOI | 10.1103/PhysRevB.94.075304 |
| ISSN | 2469-9950/2469-9969 |
| PermalinkURL | https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84981266375&origin=inward |