Magnified Damping under Rashba Spin Orbit Coupling

TL;DR

This paper investigates how Rashba spin orbit coupling can significantly amplify the damping effect of field-like spin torques in magnetic systems, with implications for magnetic memory technologies.

Contribution

It introduces a model where Rashba coupling magnifies damping of field-like spin torques, providing a new perspective on spin torque dynamics.

Findings

Rashba coupling enhances damping of field-like spin torques.

Self-consistent equations link magnetization and spin dynamics.

Potential implications for magnetic memory devices.

Abstract

The spin orbit coupling spin torque consists of the field-like [REF: S.G. Tan et al., arXiv:0705.3502, (2007).] and the damping-like terms [REF: H. Kurebayashi et al., Nature Nanotechnology 9, 211 (2014).] that have been widely studied for applications in magnetic memory. We focus, in this article, not on the spin orbit effect producing the above spin torques, but on its magnifying the damping constant of all field like spin torques. As first order precession leads to second order damping, the Rashba constant is naturally co-opted, producing a magnified field-like damping effect. The Landau-Liftshitz-Gilbert equations are written separately for the local magnetization and the itinerant spin, allowing the progression of magnetization to be self-consistently locked to the spin.