Microwave-induced dynamic switching of magnetic skyrmion cores in nanodots

TL;DR

This study demonstrates that magnetic skyrmion cores in nanodots can be reversibly switched within nanoseconds using a perpendicular oscillating magnetic field, revealing two distinct excitation modes and mechanisms.

Contribution

It introduces a numerical analysis of skyrmion core reversal via dynamic excitation modes, highlighting new switching processes distinct from vortex core reversal.

Findings

Skyrmion core reversal achieved within nanoseconds.

Two excitation modes identified: breathing and mixed modes.

Radial spin waves are not the dominant reversal mechanism.

Abstract

The nonlinear dynamic behavior of a magnetic skyrmion in circular nanodots was studied numerically by solving the Landau-Lifshitz-Gilbert equation with a classical spin model. We show that a skyrmion core reversal can be achieved within nanoseconds using a perpendicular oscillating magnetic field. Two symmetric switching processes that correspond to excitations of the breathing mode and the mixed mode (combination of the breathing mode and a radial spin-wave mode) are identified. For excitation of the breathing mode, the skyrmion core switches through nucleation of a new core from a transient uniform state. In the mixed mode, the skyrmion core reverses with the help of spins excited both at the edge and core regions. Unlike the magnetic vortex core reversal, the excitation of radial spin waves does not dominate the skyrmion core reversal process.