Lowering the skyrmion depinning current in synthetic antiferromagnetic systems

Abstract

Magnetic skyrmions, as topological spin textures, offer great potential for next-generation spintronic applications. Skyrmions in artificially synthesized antiferromagnets (SAFs) are particularly promising due to their ability to suppress the skyrmion Hall effect and achieve faster dynamics, making them highly attractive for spintronic devices. However, the critical current density required to drive SAF skyrmions using spin-transfer torque is significantly higher than in conventional ferromagnetic systems. In this work, we analytically and numerically demonstrate that the critical current density for SAF skyrmions can be significantly reduced by applying distinct currents to different layers within the system. This approach can be applied to periodically pinned skyrmions in SAFs, offering the dual benefits of a suppressed Hall effect and a reduced critical current density. Our findings pave the way for more efficient manipulation of SAF skyrmions in spintronic device architectures.