Experimental Observation of Vortex Gyration Excited by Surface Acoustic Waves

We report experiments using magnetic resonance force microscopy to investigate the dynamics of magnetic vortices in submicrometer CoFeB disks grown on a piezoelectric substrate. We compare the vortex gyration excited inductively by microwave magnetic fields and through magnetoelastic coupling via surface acoustic waves (SAWs). Based on the device geometry and modeling performed, we find that the dominant mechanism for SAW-driven excitation is through lattice rotations, which generate an effective field localized at the vortex core. This contrasts with the magnetoelastic strains typically assumed in similar experiments. Moreover, we demonstrate that this magnetorotation torque can be tuned by applying a perpendicular magnetic field. Unlike spin wave excitations, nontrivial spin textures, such as vortices, effectively couple to magnetorotation torques, making them valuable probes for studying such phenomena.