The 3D Spin-wave Modes of the Magnetic Vortex in a Thick Circular Nanodisk

Abstract

The spin-wave mode of a magnetic vortex (MV) structure is a fascinating topic in magnetism for developing signal generator of novel data processing device with low power consumption. In a confined system, the MV structure shows three different excitation modes such as translational mode, azimuthal, and radial spin-wave modes [1-3]. However, most of the studies on the spin-wave modes of MV have been performed under the assumption that the magnetization is uniform along the thickness direction. Recently, it is reported that three-dimensional (3D) nature causes flexible oscillation of the vortex core (VC) [4], which makes a rich variety of spin-wave modes of MV in a relatively thick nanodisk. In this work, we report the 3D spin-wave modes of MV, beating mode - the size oscillations of VC by performing micromagnetic simulations as shown in Fig.1, whose phase is not uniform along the thickness direction. Furthermore, we found that the VC reversals can occur through the resonant excitation of this beating mode. Interestingly, its reversal mechanism is completely different with previously known vortex-antivortex pair mediated mechanism [5]; the Bloch-point pair are created at the center of the VC structure and they propagate through the film thickness. In the presentation, we will discuss detailed mechanism and physical understandings on this novel core switching process.