Excitation modes of vortices in sub-micron magnetic disks

TL;DR

This paper develops a classical and quantum theory of spin waves in vortex states of sub-micron magnetic disks, highlighting the effects of finite vortex mass, external magnetic fields, and dissipation on vortex excitation modes.

Contribution

It introduces a comprehensive theoretical framework accounting for finite vortex mass and predicts new high-frequency spin wave modes in mesoscopic magnetic disks.

Findings

Vortex mass computed aligns with experimental data.

Finite vortex mass creates a high-frequency branch of spin waves.

External magnetic fields influence vortex excitation spectra.

Abstract

Classical and quantum theory of spin waves in the vortex state of a mesoscopic sub-micron magnetic disk has been developed with account of the finite mass density of the vortex. Oscillations of the vortex core resemble oscillations of a charged string in a potential well in the presence of the magnetic field. Conventional gyroscopic frequency appears as a gap in the spectrum of spin waves of the vortex. The mass of the vortex has been computed that agrees with experimental findings. Finite vortex mass generates a high-frequency branch of spin waves. Effects of the external magnetic field and dissipation have been addressed.