Tunable skyrmion–edge interaction in magnetic multilayers by interlayer exchange coupling

Abstract

Magnetic skyrmions are appealing for applications in emerging topological spintronic devices. However, when magnetic skyrmions in a nanowire are driven by an in-plane current, a transverse Magnus force deflects their trajectories from the current direction, which tends to push the skyrmion toward the edge. If the current density is exceedingly large, the skyrmion will be annihilated around the edge, leading to a greatly reduced propagation distance and a maximum speed of the skyrmion, which is detrimental to skyrmion-based spintronic applications. Here, we prepare a magnetic multilayer Ta/[Pt/Co]3/Ru/[Co/Pt]3 and tailor the interlayer exchange coupling strength by varying the thickness of the Ru layer. Based on the magneto-optic Kerr effect microscope, we find that the skyrmion–edge interaction is tunable by the interlayer exchange coupling strength, namely, the strength of the repulsive potential from the film edge is tailored by the interlayer exchange coupling strength. Our results unveil the significant role of the interlayer exchange coupling in skyrmion dynamics.