Interfacial spin-orbit torques

Published

October 21, 2020

Author(s)

Vivek P. Amin, Paul M. Haney, Mark D. Stiles

Abstract

Spin-orbit torques offer a promising mechanism to electrically control magnetization dynamics in nanoscale heterostructures. While spin-orbit torques occur predominately at interfaces, the physical mechanisms underlying these torques can originate in both the bulk layers and at interfaces. Classifying spin-orbit torques based on the region that they originate in provides clues as to how to optimize the effect. While most bulk spin-orbit torque contributions are well studied, many of the interfacial contributions suggested on phenomenological grounds have yet to be fully explored theoretically and experimentally. To facilitate progress, we review interfacial spin-orbit torques from a semiclassical viewpoint and relate these contributions to recent experimental results. Within the same model, we show the relationship between different interface transport parameters. For perpendicular transport, interfacial spin-orbit coupling modifies the mixing conductance of magnetoelectronic circuit theory and gives rise to spin memory loss. For in-plane transport, spin-orbit coupling gives rise to torques described by spin-orbit filtering, spin swapping and precession. In addition, these same processes generate spin currents at the interface that can flow into the non-magnetic layer. In trilayer structures, these spin currents can propagate through the non-magnetic layer to produce novel torques on the other ferromagnetic layer.

Citation

Journal of Applied Physics

Volume

128

Issue

15

Pub Type

Journals

Download Paper

https://doi.org/10.1063/5.0024019

Local Download

Keywords

spin-orbit coupling, magnetic multilayer, spin-orbit torque, magnetization dynamics, spin- transfer torque

Citation

Amin, V. , Haney, P. and Stiles, M. (2020), Interfacial spin-orbit torques, Journal of Applied Physics, [online], https://doi.org/10.1063/5.0024019, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=930671 (Accessed October 31, 2024)