Surface-assisted spin Hall effect in Au films with Pt impurities

プラチナ不純物を持つ金薄膜における表面寄与によるスピンホール効果

Gu, B.; 管井 勇*; Ziman, T.*; Guo, G. Y.*; 永長 直人; 関 剛斎*; 高梨 弘毅; 前川 禎通

Gu, B.; Sugai, Isamu*; Ziman, T.*; Guo, G. Y.*; Nagaosa, Naoto; Seki, Takeshi*; Takanashi, Koki; Maekawa, Sadamichi

We show, both experimentally and theoretically, a novel route to obtain giant room temperature spin Hall effect due to surface-assisted skew scattering. In the experiment, we report the spin Hall effect in Pt-doped Au films with different thicknesses . The giant spin Hall angle = is obtained for = 10 nm at room temperature, while it is much smaller for = 20 nm sample. Combined and quantum Monte Carlo calculations for the skew scattering due to a Pt impurity show 0.1 on the Au (111) surface, while it is small in bulk Au. The quantum Monte Carlo results show that the spin-orbit interaction of the Pt impurity on the Au (111) surface is enhanced, because the Pt 5 levels are lifted to the Fermi level due to the valence fluctuation. In addition, there are two spin-orbit interaction channels on the Au (111) surface, while only one in bulk Au.