Strong photon–magnon coupling at microwave and millimeter-wave frequencies in planar hybrid circuits

Photon–magnon hybrid systems have potential applications in modern information processing technologies. Although planar circuits based on split ring resonators shown strong coherent photon–magnon coupling, none of those operates at millimeter-wave frequencies. With specially designed electric-field-coupled resonators, coupling between resonator modes and ferromagnetic resonance (either in-plane or out-of-plane) was experimentally observed two working 4.1 30 GHz. Their dynamics were well described by quantum models. The miniature, integrable, physically robust pave a way for even higher frequencies, demonstrating the possibility to integrate magnon-based with devices.