Magnonic frequency comb through nonlinear magnon-skyrmion scattering

TL;DR

This paper theoretically predicts and verifies the generation of a magnonic frequency comb through nonlinear magnon-skyrmion scattering, with tunable mode spacing, opening new avenues in magnonic and spintronic applications.

Contribution

It introduces the concept of magnonic frequency combs generated by nonlinear magnon-skyrmion interactions, a novel phenomenon not previously reported in magnonic systems.

Findings

Magnonic frequency combs can be generated above a threshold amplitude.

The mode spacing equals the skyrmion's breathing mode frequency.

The frequency comb's properties are tunable via electric or magnetic means.

Abstract

An optical frequency comb consists of a set of discrete and equally spaced frequencies and has found wide applications in the synthesis over broad spectral frequencies of electromagnetic wave and precise optical frequency metrology. Despite the analogies between magnons and photons in many aspects, the analogue of optical frequency comb in magnonic system has not been reported. Here, we theoretically study the magnon-skyrmion interaction and find that magnonic frequency comb (MFC) can be generated above a threshold of driving amplitude, where the nonlinear scattering process involving three magnons prevails. The mode-spacing of the MFC is equal to the breathing-mode frequency of skyrmion and is thus tunable by either electric or magnetic means. The theoretical prediction is verified by micromagnetic simulations and the essential physics can be generalized to a large class of magnetic solitons. Our findings open a new pathway to observe the frequency comb structure in magnonic devices, that may inspire the study of fundamental nonlinear physics in spintronic platform in the future.