Gyrotropic skyrmion modes in ultrathin magnetic circular dots

TL;DR

This paper calculates the low-frequency gyrotropic spin excitation modes of skyrmions in ultrathin magnetic dots, providing insights into their dynamics and potential applications in spintronics.

Contribution

It introduces a theoretical framework for calculating gyrotropic modes of skyrmions in ultrathin dots considering various magnetic interactions and compares with recent experimental findings.

Findings

Gyrotropic frequencies are in the GHz range.

Skyrmion size and dot parameters significantly influence the modes.

Theoretical results align with recent experimental observations.

Abstract

We calculate low-frequency gyrotropic spin excitation modes of the skyrmion ground state ultrathin cylindrical magnetic dots. The skyrmion is assumed to be stabilized at room temperature and zero external magnetic field due to an interplay of the isotropic and Dzyaloshinskii-Moriya exchange interactions, perpendicular magnetic anisotropy and magnetostatic interaction. We consider Bloch- and Neel-type magnetic skyrmions and assume that the dot magnetization does not depend on the thickness coordinate. The skyrmion gyrotropic frequencies are calculated in GHz range as a function of the skyrmion equilibrium radius, dot radius and the dot magnetic parameters. Recent experiments on magnetic skyrmion gyrotropic dynamics in nanodots are discussed.