Stabilization and dynamics of magnetic antivortices in a nanodisk with anisotropic Dzyaloshinskii-Moriya interaction

TL;DR

This paper theoretically explores the stability and dynamic behavior of magnetic antivortices in nanodisks influenced by anisotropic Dzyaloshinskii-Moriya interaction, revealing their stability at nanoscale and responses to magnetic fields and currents.

Contribution

It demonstrates the stability of antivortices at very small nanodisk sizes due to short-range DMI and analyzes their dynamic responses to magnetic fields and spin-polarized currents.

Findings

Antivortices remain stable in nanodisks as small as 15 nm.

Displacement of antivortex core depends on vorticity and helicity.

Spin-polarized currents induce antivortex gyration and polarity switching.

Abstract

We theoretically investigate the antivortex stabilized by anisotropic Dzyaloshinskii-Moriya interaction (DMI) in nanodisks. It is remarkably found that the antivortex remains stable even when the nanodisk radius is reduced to 15 nm, owing to the short-range nature of the DMI. We also investigate the antivortex dynamics under a static in-plane magnetic field, which shows that the displacement of the antivortex core depends on its vorticity and helicity, providing a fundamental basic for distinguishing different vortex types. Additionally, spin-polarized currents can trigger a self-sustained gyration of the antivortex at low current densities, while inducing polarity switching at high current densities. Our findings offer valuable insights into the DMI role in stabilizing topological solitons and their potential applications in spin-torque nano-oscillators and magnetic memories.