Stimulated amplification of propagating spin waves

TL;DR

This paper presents a new method for amplifying propagating spin waves in magnonic nanostructures using rapid cooling to create a non-equilibrium magnon state, enabling stimulated amplification.

Contribution

It introduces a novel amplification mechanism based on rapid cooling and non-equilibrium magnons, advancing magnonic computing technology.

Findings

Demonstrated stimulated amplification of spin waves

Identified energy flux from high-energy magnons to propagating modes

Validated the mechanism with an extended kinetic model

Abstract

Spin-wave amplification techniques are key to the realization of magnon-based computing concepts. We introduce a novel mechanism to amplify spin waves in magnonic nanostructures. Using the technique of rapid cooling, we create a non-equilibrium state in excess of high-energy magnons and demonstrate the stimulated amplification of an externally seeded, propagating spin wave. Using an extended kinetic model, we qualitatively show that the amplification is mediated by an effective energy flux of high energy magnons into the low energy propagating mode, driven by a non-equilibrium magnon distribution.