Keywords:Spin injection, Inverse spin Hall effect, Ferromagnetic semiconductors
Room-temperature spin injection using ferromagnetic semiconductors is a building block for the realization of spin-functional semiconductor devices. Nevertheless, this has been very challenging due to the lack of reliable room-temperature ferromagnetism in well-known group IV and III-V semiconductors. We demonstrate the first room-temperature spin injection by spin pumping in a (Ga,Fe)Sb/ BiSb heterostructure, where (Ga,Fe)Sb is a ferromagnetic semiconductor with high Curie temperature (> 300 K) and BiSb is a topological insulator. Despite the very small magnetization of (Ga,Fe)Sb at room temperature (45 emu/cc), we clearly detect spin injection from (Ga,Fe)Sb by utilizing the inverse spin Hall effect in the topological surface states of BiSb with a large inverse spin Hall angle of 2.5. Our study provides the first and important step towards efficient spin injection and detection for practical semiconductor spintronics devices operating at room temperature.
This work was partly supported by Grants-in-Aid for Scientific Research (Nos. 17H04922 and 18H03860, and 20H05650), CREST of JST (JPMJCR1777, JPMJCR18T5), and Spin-RNJ.
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