Frequency comb in twisted magnonic crystals

TL;DR

This paper demonstrates the generation of magnonic frequency combs in twisted magnonic crystals, revealing how twist angles and excitation frequencies influence nonlinear magnon interactions and comb quality.

Contribution

It introduces the creation of magnonic frequency combs in twisted magnonic crystals and explores how twist angles enhance nonlinear magnon interactions.

Findings

Finite twist angles significantly enhance three-magnon interactions.

Number of comb teeth depends on twist angle and excitation frequency.

Optimal twist angles and frequencies exist for high-quality magnonic frequency combs.

Abstract

While twisted magnonic crystals (MCs) have recently gained attention for their intriguing linear phenomena, such as magnon flat bands, their nonlinear dynamics -- particularly the generation of magnonic frequency combs (MFCs) -- have remained largely unexplored. In this work, we demonstrate the creation of MFCs in twisted MCs using two-tone microwave excitation. We find that finite twist angles significantly enhance three-magnon interactions, driven by the non-collinear ground-state magnetic configuration induced by interlayer dipole-dipole interactions. The number of comb teeth exhibits a plateau-like dependence on the twist angle, with the plateau's width and height saturating as the excitation frequency of the propagating magnon mode increases. This behavior reveals an optimal range of twist angles and frequencies for achieving high-quality MFCs with a large number of comb teeth. Our findings deepen the understanding of nonlinear interactions in twisted MCs and highlight their potential for advancing moir\'e-based materials in information processing and high-precision metrology.