Sub-nanosecond switching of vortex cores using a resonant perpendicular magnetic field

Abstract

We performed micromagnetic numerical studies on ultrafast switching of magnetic vortex cores (VCs) using a perpendicular magnetic field that oscillates at the eigenfrequency of a permalloy nanodisk. Our calculations show that a resonant magnetic field with amplitude of 30 mT stimulates strong axially symmetric magnetization oscillation and forces the vortex core to stay at the center of the nanodisk. The compression of the vortex core by spin wave leads to core reversal at 602 ps. This switching process is mediated by the propagation of a Neel wall across the sample thickness.