Statics and Dynamics of Skyrmions in Balanced and Unbalanced Synthetic Antiferromagnets

TL;DR

This paper investigates the static and dynamic properties of skyrmions in synthetic antiferromagnets, revealing advantages like smaller size and higher velocity, supported by simulations and an analytical model, with implications for spintronic applications.

Contribution

It provides the first comprehensive numerical and analytical study of skyrmions in balanced and unbalanced synthetic antiferromagnets, highlighting their improved properties over ferromagnetic layers.

Findings

Reduced skyrmion radius in SAFs

Increased skyrmion velocity under current

Vanishing topological deflection in SAFs

Abstract

Synthetic antiferromagnets have great potential as skyrmion carriers in which new properties are expected for these spin textures, owing to changed magnetostatics and the absence of net topological charge. Here we numerically simulate the static and dynamic behaviour of skyrmions in these systems and clearly highlight the benefits compared to ferromagnetic single layers. In particular, our results show a reduction of the skyrmion radius, an increase of their velocity under current, and a vanishing of their topological deflection. We also provide a robust and straightforward analytical model that captures the physics of such skyrmions. Finally, by extending the model to the case of an unbalanced SAF, we show some conditions for the system that optimise the properties of the skyrmion for potential spintronic devices.