Dynamic Origin of Vortex Core Switching in Soft Magnetic Nanodots

TL;DR

This paper investigates the physical mechanism behind vortex core switching in soft magnetic nanodots, revealing that a gyrotropic field induced by vortex motion causes core reversal, which is crucial for magnetic memory applications.

Contribution

It provides an analytical and micromagnetic explanation of vortex core reversal, highlighting the role of the gyrotropic field generated by vortex dynamics.

Findings

Vortex core reversal is caused by a gyrotropic field.

The gyrotropic field is proportional to vortex velocity.

Understanding this mechanism aids in controlling vortex core states.

Abstract

The magnetic vortex with the in-plane curling magnetization and the out-of-plane magnetization at the core is a unique ground state in nanoscale magnetic elements. This kind of magnetic vortex can be used as a memory unit for information storage, through its downward or upward core-orientation and, thus, controllable core switching deserves some special attention. Our analytical and micromagnetic calculations reveal that the origin of the vortex core reversal is a gyrotropic field. This field is induced by vortex dynamic motion and is proportional to the velocity of the moving vortex. Our calculations elucidate the physical origin of the vortex core dynamic reversal and offer a key to effective manipulation of the vortex-core orientation.