Chirality from interfacial spin-orbit coupling effects in magnetic bilayers

TL;DR

This paper investigates how interfacial spin-orbit coupling in magnetic bilayers induces chirality, affecting magnetization dynamics and linking Dzyaloshinskii-Moriya interaction with spin-orbit torque, with implications for nanomagnetic device design.

Contribution

It introduces a simplified Rashba model to analyze interfacial spin-orbit effects and reveals a correlation between Dzyaloshinskii-Moriya interaction and spin-orbit torque.

Findings

Chirality arises from interfacial spin-orbit coupling.

Linear contributions follow from chirality, simplifying analysis.

Correlation between Dzyaloshinskii-Moriya interaction and spin-orbit torque.

Abstract

As nanomagnetic devices scale to smaller sizes, spin-orbit coupling due to the broken structural inversion symmetry at interfaces becomes increasingly important. Here we study interfacial spin-orbit coupling effects in magnetic bilayers using a simple Rashba model. The spin-orbit coupling introduces chirality into the behavior of the electrons and through them into the energetics of the magnetization. In the derived form of the magnetization dynamics, all of the contributions that are linear in the spin-orbit coupling follow from this chirality, considerably simplifying the analysis. For these systems, an important consequence is a correlation between the Dzyaloshinskii-Moriya interaction and the spin-orbit torque. We use this correlation to analyze recent experiments.