Dynamics of the antiferromagnetic skyrmion induced by a magnetic anisotropy gradient

TL;DR

This paper investigates how a magnetic anisotropy gradient can be used to manipulate antiferromagnetic skyrmions, providing analytical and numerical insights that could inform future spintronic device design.

Contribution

It introduces a novel method using magnetic anisotropy gradients to control insulating antiferromagnetic skyrmions, expanding the manipulation techniques beyond electric currents.

Findings

Anisotropy gradient drives skyrmions towards lower anisotropy regions.

Analytical and micromagnetic results are in good agreement.

Skyrmion velocity under anisotropy gradient is comparable to ferromagnetic cases.

Abstract

The dynamics of antiferromagnets is a current hot topic in condensed matter physics and spintronics. However, the dynamics of insulating antiferromagnets cannot be excited by an electric current, which is a method usually used to manipulate ferromagnetic metals. Here, we propose to use the voltage-controlled magnetic anisotropy gradient as an excitation source to manipulate insulating antiferromagnetic textures. We analytically and numerically study the dynamics of an antiferromagnetic skyrmion driven by a magnetic anisotropy gradient. Our analytical calculations demonstrate that such a magnetic anisotropy gradient can effectively drive an antiferromagnetic skyrmion towards the area of lower magnetic anisotropy. The micromagnetic simulations are in good agreement with our analytical solution. Furthermore, the magnetic anisotropy gradient induced velocity of an antiferromagnetic skyrmion is compared with that of a ferromagnetic skyrmion. Our results are useful for the understanding of antiferromagnetic skyrmion dynamics and may open a new way for the design of antiferromagnetic spintronic devices.