The enhanced spin Hall effect in Au metal due to the resonant skew scattering is studied with first-principles band structure calculations. Especially the gigantic spin Hall angle γS≅0.1 observed recently (T.Seki et al., Nature Materials {\bf 7}, 125 (2008)) is attributed to the orbital-dependent Kondo effect of Fe in the Au host metal, where the t2g-orbitals are in the mixed-valence region while eg-orbitals are in the Kondo limit. The enhanced spin-orbit interaction by the electron correlation in the t2g-orbitals leads to the gigantic spin Hall effect. Impurities with 5d orbitals are also discussed.
@article{arxiv.0809.2921,
title = {Enhanced spin Hall effect by resonant skew scattering in orbital-selective Kondo effect},
author = {Guang-Yu Guo and Sadamichi Maekawa and Naoto Nagaosa},
journal= {arXiv preprint arXiv:0809.2921},
year = {2009}
}