Regensburg 2019 – wissenschaftliches Programm
MA 38.1: Vortrag
Mittwoch, 3. April 2019, 17:15–17:30, H52
Spin-Charge Conversion in NiMnSb Alloy Films — Zhenchao Wen1,2, Zhiyong Qiu2,3, •Sebastian Tölle4, Cosimo Gorini5, Takeshi Seki2, Dazhi Hou2, Takahide Kubota2, Ulrich Eckern4, Eiji Saitoh2, and Koki Takanashi2 — 1NIMS, Tsukuba, Japan — 2Tohoku University, Sendai, Japan — 3Dalian University of Technology, Dalian, China — 4University of Augsburg, Germany — 5University of Regensburg, Germany
Heterostructures with half-metallic ferromagnets (HMF) such as NiMnSb represent an interesting platform for various spin-charge conversion processes since (1) perfect HMFs have the unique property that their conduction electrons are fully spin-polarized at zero temperature, and (2) the interface can exhibit spin-orbit effects, e.g., Rashba spin-orbit coupling. In this work, we study the spin to charge conversion in NiMnSb/YIG bilayers, with YIG serving as a spin pump. Due to spin-orbit coupling, the injected spin current results in a transverse voltage which shows an unusual temperature dependence with a thickness-dependent sign change. We explain this behaviour by two competing contributions, a temperature independent one due to the interface and a bulk contribution, different in sign, which originates from minority-spin electrons due to thermally excited magnons.