Proposed controlled creation and manipulation of skyrmions with spin–orbit torque

Abstract

The physical mechanisms underlying current-driven skyrmion motion include the spin-transfer torque exerted by a spin-polarized horizontal electric current and the spin–orbit torque exerted by a perpendicular spin current. Each mechanism requires a specific sample geometry and structural configuration. Regarding current-induced skyrmion creation, skyrmions can be efficiently created at low current densities via spin-transfer torque when an electric current is applied to a nanotrack structure with a small notch. However, an effective and controlled method for skyrmion creation via spin–orbit torque in notched nanotracks has yet to be established. Here, we theoretically propose a method for the creation, driving, and deletion of skyrmions in a three-terminal magnetic heterojunction with a notch. Our proposal offers valuable insights into the design of techniques for skyrmion creation and manipulation using spin–orbit torque, which is essential for technical applications of magnetic skyrmions as information carriers in next-generation spintronic memory devices.