Spin-wave frequency combs

TL;DR

This paper demonstrates the experimental generation of spin-wave frequency combs through nonlinear interactions in a microstructured waveguide, with tunable spectral properties and a theoretical model explaining the underlying four-magnon scattering process.

Contribution

It introduces the first experimental realization of spin-wave frequency combs and a model for stimulated four-magnon scattering in this context.

Findings

Successful generation of tunable spin-wave frequency combs

Observation of cascade four-magnon scattering events

Development of a theoretical model for comb formation

Abstract

We experimentally demonstrate the generation of spin-wave frequency combs based on the nonlinear interaction of propagating spin waves in a microstructured waveguide. By means of time and space-resolved Brillouin light scattering spectroscopy, we show that the simultaneous excitation of spin waves with different frequencies leads to a cascade of four-magnon scattering events which ultimately results in well-defined frequency combs. Their spectral weight can be tuned by the choice of amplitude and frequency of the input signals. Furthermore, we introduce a model for stimulated four-magnon scattering which describes the formation of spin-wave frequency combs in the frequency and time domain.