Dynamics of Vortex Core Switching in Ferromagnetic Nanodisks

TL;DR

This paper investigates the process of vortex core switching in ferromagnetic nanodisks using micromagnetic modeling, revealing how magnetic field pulses induce vortex-antivortex dynamics leading to core reversal.

Contribution

It provides a detailed micromagnetic simulation study of vortex core switching mechanisms in nanodisks, highlighting the role of vortex-antivortex pairs and spin wave propagation.

Findings

Vortex-antivortex pairs are created during core switching.

Spin waves propagate through the disk during annihilation.

The system relaxes into a single vortex state with a reversed core.

Abstract

Dynamics of magnetic vortex core switching in nanometer-scale permalloy disk, having a single vortex ground state, was investigated by micromagnetic modeling. When an in-plane magnetic field pulse with an appropriate strength and duration is applied to the vortex structure, additional two vortices, i.e., a circular- and an anti-vortex, are created near the original vortex core. Sequentially, the vortex-antivortex pair annihilates. A spin wave is created at the annihilation point and propagated through the entire element; the relaxed state for the system is the single vortex state with a switched vortex core.