Spin-torque resonance due to diffusive dynamics at a surface of topological insulator

Autor: Sokolewicz, R. J., Ado, I. A., Katsnelson, M. I., Ostrovsky, P. M., Titov, M.
Rok vydání: 2018
Předmět:
Zdroj: Phys. Rev. B 99, 214444 (2019)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevB.99.214444
Popis: We investigate spin-orbit torques on magnetization in an insulating ferromagnetic (FM) layer that is brought into a close proximity to a topological insulator (TI). In addition to the well-known field-like spin-orbit torque, we identify an anisotropic anti-damping-like spin-orbit torque that originates in a diffusive motion of conduction electrons. This diffusive torque is vanishing in the limit of zero momentum (i. e. for spatially homogeneous electric field or current), but may, nevertheless, have a strong effect on spin-torque resonance at finite frequency provided external field is neither parallel nor perpendicular to the TI surface. The required electric field configuration can be created by a grated top gate.
Comment: 10 page main text, 3 figures
Databáze: arXiv