We experimentally observe the generation of magnon harmonics and subharmonics in an on-chip surface acoustic wave resonator incorporating a thin Co20Fe60B20 film, using micro-focused Brillouin light scattering. In our devices, rotating the in-plane magnetic field allows continuous tuning of the magnon-phonon coupling from weak to strong within the same resonator. In the weak coupling regime, we only observe fundamental magnetoelastic wave signal at f1. Conversely, in the strong coupling regime, in addition to the fundamental magnetoelastic wave, we observe subharmonic and harmonic signals at 3/2f1, 2f1, and 3f1, which are well reproduced by our analytical model. Our results establish phonons as a means to generate and control nonlinear magnons in the strong coupling regime, providing a new route for magnonic signal processing.
@article{arxiv.2509.19706,
title = {Harmonic and Subharmonic Magnon Generation in a Surface Acoustic Wave Resonator},
author = {Yunyoung Hwang and Liyang Liao and Jorge Puebla and Marco Brühlmann and Carlos Gonzalez-Ballestero and Kouta Kondou and Naoki Ogawa and Sadamichi Maekawa and Yoshichika Otani},
journal= {arXiv preprint arXiv:2509.19706},
year = {2025}
}