Frequency multiplication involves generating harmonics from an input frequency, a technique particularly useful for integrating spin-wave devices operating at different frequencies. While topological magnetic textures offer distinct advantages in spin-wave applications, frequency multiplication has not yet been observed in these structures. Here, we study the magnetization dynamics of magnetic vortices formed in micron-sized disks and squares via wide-field magnetic imaging. We found the occurrence of coherent spin-wave harmonics arising from the gyration of vortex cores driven by microwave fields. This phenomenon reveals a universal mechanism where the periodical motion of delta function-like objects such as vortex cores gives rise to a frequency comb. Our results pave the way for creating nanoscale, tunable spin-based frequency multipliers and open new possibilities for frequency comb generation in a variety of systems.
@article{arxiv.2412.13784,
title = {Spin-wave frequency multiplication by magnetic vortex cores},
author = {Cheng-Jie Wang and Yuxin Li and Zhe Ding and Pengfei Wang and Fazhan Shi and Jiangfeng Du},
journal= {arXiv preprint arXiv:2412.13784},
year = {2024}
}