Excitation of spin wave modes of a magnetic dot existing in a shifted vortex-state by an out-of-plane oscillating magnetic field

TL;DR

This study numerically investigates how an out-of-plane oscillating magnetic field excites spin wave modes in a vortex-state magnetic dot, revealing effects of static in-plane fields on vortex core dynamics and mode interactions.

Contribution

It demonstrates that static in-plane magnetic fields shift the vortex core and enable selective excitation of azimuthal spin waves, affecting vortex dynamics through nonlinear interactions.

Findings

Static in-plane field shifts vortex core position.

Perpendicular oscillating field excites azimuthal dipolar spin waves.

Dipolar spin waves influence the gyrotropic mode's dissipation rate.

Abstract

Excitation of spin wave modes of a vortex-state magnetic dot by an out-of-plane oscillating magnetic field is studied numerically in the presence of a static in-plane magnetic field. It is shown, that the application of the in-plane static field shifts the position of the vortex core and leads to the separate excitation of different azimuthal dipolar spin waves my perpendicular oscillating field. It is also shown that the excited dipolar azimuthal spin waves excite the gyrotropic mode of the vortex core rotation and, depending on the excitation frequency, cause a significant modification (increase or decrease) of the apparent dissipation rate of the gyrotropic mode. The last effect can be explained by the nonlinear parametric interaction between the gyrotropic mode and the dipolar spin wave modes with different azimuthal indices.