Lee Soobeom, Koike Hayato, Goto Minori, Miwa Shinji, Suzuki Yoshishige, Yamashita Naoto, Ohshima Ryo, Shigematsu Ei, Ando Yuichiro, Shiraishi Masashi
Department of Electronic Science and Engineering, Kyoto University, Kyoto, Kyoto, Japan.
Advanced Products Development Center, TDK Corporation, Ichikawa, Chiba, Japan.
Nat Mater. 2021 Sep;20(9):1228-1232. doi: 10.1038/s41563-021-01026-y. Epub 2021 Jun 3.
The spin-orbit interaction (SOI), mainly manifesting itself in heavy elements and compound materials, has been attracting much attention as a means of manipulating and/or converting a spin degree of freedom. Here, we show that a Si metal-oxide- semiconductor (MOS) heterostructure possesses Rashba-type SOI, although Si is a light element and has lattice inversion symmetry resulting in inherently negligible SOI in bulk form. When a strong gate electric field is applied to the Si MOS, we observe spin lifetime anisotropy of propagating spins in the Si through the formation of an emergent effective magnetic field due to the SOI. Furthermore, the Rashba parameter α in the system increases linearly up to 9.8 × 10 eV m for a gate electric field of 0.5 V nm; that is, it is gate tuneable and the spin splitting of 0.6 μeV is relatively large. Our finding establishes a family of spin-orbit systems.
自旋轨道相互作用（SOI）主要在重元素和复合材料中表现出来，作为一种操纵和/或转换自旋自由度的手段，它一直备受关注。在此，我们表明，硅金属氧化物半导体（MOS）异质结构具有Rashba型SOI，尽管硅是轻元素且具有晶格反演对称性，导致其体形式的SOI本质上可忽略不计。当向硅MOS施加强栅极电场时，由于SOI形成了一个出射有效磁场，我们观察到硅中传播自旋的自旋寿命各向异性。此外，对于0.5 V/nm的栅极电场，系统中的Rashba参数α线性增加至9.8×10 eV·m；也就是说，它是可通过栅极调节的，并且0.6 μeV的自旋分裂相对较大。我们的发现建立了一个自旋轨道系统家族。
