We report the observation of a spin-orbit torque (SOT) originating from the surface Rashba-Edelstein effect. We found that the SOT in a prototypical spin-orbitronic system, a Pt/Co bilayer, can be manipulated by molecular self-assembly on the Pt surface. This evidences that the Rashba spin-orbit coupling at the Pt surface generates a sizable SOT, which has been hidden by the strong bulk and interface spin-orbit coupling. We show that the molecular tuning of the surface Rashba-Edelstein SOT is consistent with density functional theory calculations. These results illustrate the crucial role of the surface spin-orbit coupling in the SOT generation, which alters the landscape of metallic spin-orbitronic devices.
@article{arxiv.2004.09852,
title = {Surface Rashba-Edelstein Spin-Orbit Torque Revealed by Molecular Self-Assembly},
author = {Satoshi Haku and Atsushi Ishikawa and Akira Musha and Hiroyasu Nakayama and Takashi Yamamoto and Kazuya Ando},
journal= {arXiv preprint arXiv:2004.09852},
year = {2020}
}