Spin-current-driven thermoelectric generation based on interfacial spin-orbit coupling

Yagmur, A.*; 軽部 修太郎*; 内田 健一*; 近藤 浩太*; 井口 亮*; 吉川 貴史*; 大谷 義近*; 齊藤 英治

Applied Physics Letters, 108(24), p.242409_1 - 242409_4, 2016/06

https://doi.org/10.1063/1.4953879

The longitudinal spin Seebeck effect (SSE) in Bi O/Cu/yttrium-iron-garnet (YIG) devices has been investigated. When an out-of-plane temperature gradient is applied to the BiO/Cu/YIG device, a spin current is generated across the Cu/YIG interface via the SSE and then converted into electric voltage due to the spinO/Cu interface. The sign of the SSE voltage in the BiO/Cu/YIG devices is opposite to that induced by the conventional inverse spin Hall effect in Pt/YIG devices. The SSE voltage in the BiO/Cu/YIG devices disappears in the absence of the BiOlayer and its thermoelectric conversion efficiency is independent of the Cu thickness, indicating the important role of the BiO/Cu interface. This result demonstrates that not only the bulk inverse spin Hall effect but also the spin-orbit coupling near the interface can be used for SSE-based thermoelectric generation.