We predict spin Hall angles up to 80% for ultrathin noble metal films with substitutional Bi impurities. The colossal spin Hall effect is caused by enhancement of the spin Hall conductivity in reduced sample dimension and a strong reduction of the charge conductivity by resonant impurity scattering. These findings can be exploited to create materials with high efficiency of charge to spin current conversion by strain engineering.
@article{arxiv.1312.6539,
title = {Colossal Spin Hall Effect in Ultrathin Metallic Films},
author = {Christian Herschbach and Dmitry V. Fedorov and Martin Gradhand and Ingrid Mertig},
journal= {arXiv preprint arXiv:1312.6539},
year = {2014}
}