Theoretically proposed controlled creation of Bloch-type skyrmions with spin-orbit torque in a chiral-ferromagnet/heavy-metal heterojunction

The creation and manipulation of magnetic skyrmions in magnetic bilayer heterostructures via spin-orbit torque have been intensively studied in spintronics because of their potential application as information carriers in next-generation magnetic memory devices. However, experimental attempts have not always been successful. In this paper, we theoretically elucidate the underlying reasons for these difficulties and propose a practical method to overcome them by employing magnetic bilayer heterostructures that incorporate a chiral ferromagnetic layer hosting Bloch-type skyrmions instead of a conventional ferromagnetic layer hosting Neel-type skyrmions. Our micromagnetic simulations demonstrate that Bloch-type skyrmions can be controllably created in this system via spin-orbit torque exerted by a perpendicular spin current. This finding provides a promising platform and method for realizing skyrmion-based spintronic devices.