Multimode magnon-phonon polarons in a thick ferromagnetic film on a surface acoustic wave resonator

We have studied magnon-phonon coupling in a thick ferromagnetic film where the multiple magnon modes simultaneously couples to a surface acoustic wave (SAW). Owing to the spatial mode matching between phonons and magnons, a strong coupling regime is achieved to the hybridized multiple magnon modes via dipole-dipole interactions. In addition to the theoretical interpretation, we will report our recent experimental progress showing strong magnon-phonon coupling in a 6-μm YIG film integrated with a piezoelectric SAW resonator.