Polarization Selective Magnetic Vortex Dynamics and Core Reversal in Rotating Magnetic Fields

Abstract

We report on the observation of magnetic vortex dynamics in response to rotating magnetic fields in submicron platelets. Unlike linear fields
or spin polarized currents, which excite both vortex core polarization
states, an in-plane rotating field can selectively excite one of the
polarization states. We demonstrate by direct imaging with
time-resolved scanning x-ray microscopy that the rotating field only
excites the gyrotropic mode if the rotation sense of the field
coincides with the vortex gyration sense and that such a field can
selectively reverse the vortex polarization.