Control of magnon-photon coupling by spin torque

TL;DR

This paper presents a method to control magnon-photon coupling by manipulating damping and field-like torques through spin torque effects, enabling dynamic tuning of hybridized mode gaps in magnetic systems.

Contribution

It introduces a theoretical framework integrating Landau-Lifshitz-Gilbert and RLC equations to demonstrate control of magnon-photon coupling via spin torque effects.

Findings

The hybridized mode gap can be tuned by changing the dc current direction.

Control is feasible in yttrium iron garnet/Pt hybrid structures.

Damping parameter of order 10^{-3} is sufficient for control.

Abstract

We demonstrate the influence of damping and field-like torques in the magnon-photon coupling process by classically integrating the generalized Landau-Lifshitz-Gilbert equation with RLC equation in which a phase correlation between dynamic magnetization and microwave current through combined Amp\`ere and Faraday effects are considered. We show that the gap between two hybridized modes can be controlled in samples with damping parameter in the order of $10^{-3}$ by changing the direction of the dc current density $J$ if a certain threshold is reached. Our results suggest that an experimental realization of the proposed magnon-photon coupling control mechanism is feasible in yttrium iron garnet/Pt hybrid structures.