Interlayer coupling effect on skyrmion dynamics in synthetic antiferromagnets

Abstract

Skyrmions in synthetic antiferromagnets (SAFs) could be immune to the skyrmion Hall effect and are, thus, promising in spintronics applications. We introduce breathing modes that can be realized by changing the magnetocrystalline anisotropy periodically in time to generate spin waves around a deformed SAF skyrmion. The net momentum transferred from the magnon spin currents results in a motion of the SAF skyrmion, which is two orders of magnitude faster than that of a ferromagnetic skyrmion. We also reveal that the velocity of the SAF skyrmion can be manipulated by the strength of antiferromagnetic coupling between layers, which is different from ferromagnetic and antiferromagnetic systems. This phenomenon originates from the damping-like character of the antiferromagnetic coupling and offers a dimension to optimize skyrmion dynamics in SAFs.