Current-induced spin torque resonance of magnetic insulators affected by field-like spin-orbit torques and out-of-plane magnetizations

TL;DR

This paper provides a theoretical model of spin-torque ferromagnetic resonance in magnetic insulator/metal bilayers, accounting for various magnetization directions and field-like spin-orbit torques, to better understand spin-orbit interactions.

Contribution

It introduces a comprehensive theoretical framework for ST-FMR in magnetic insulator/metal bilayers considering all magnetization orientations and field-like spin-orbit torques.

Findings

Model captures all magnetization directions.

Incorporates field-like spin-orbit torques.

Helps interpret ST-FMR experiments.

Abstract

The spin-torque ferromagnetic resonance (ST-FMR) in a bilayer system consisting of a magnetic insulator such as Y3Fe5O12 and a normal metal with spin-orbit interaction such as Pt is addressed theoretically. We model the ST-FMR for all magnetization directions and in the presence of field-like spin-orbit torques based on the drift-diffusion spin model and quantum mechanical boundary conditions. ST-FMR experiments may expose crucial information about the spin-orbit coupling between currents and magnetization in the bilayers.