Spin orbit torque manipulation of kπ-skyrmions in racetrack nanostructures for spintronic memory applications

k π -skyrmions are topological magnetic textures with promising applications in spintronic devices. In this work, we investigated the stability and current-driven dynamics of k π -skyrmions ( k = 1,2,3 , and 4) in racetrack nanostructures. Stability phase diagrams were constructed as a function of the interfacial Dzyaloshinskii–Moriya interaction strength ( D int ) and the perpendicular magnetic field ( B z ). Our results showed that the stabilization range of each k π -skyrmion strongly depends on D int . In addition, the diameters of all textures increased with increasing D int and decreased with increasing B z . The current-driven dynamics induced by spin–orbit torque were then investigated. Our results showed that the velocity of all k π -skyrmions increased with current density and decreased with perpendicular magnetic field. Although the 3 π -skyrmion exhibited larger longitudinal velocities during the transient regime than the π -skyrmion, both textures reached nearly identical steady-state velocities. A similar behavior was observed for the 2 π - and 4 π -skyrmions. The steady-state dynamics were further analyzed using the Thiele formalism, which reproduced the trends observed in the micromagnetic simulations. These findings provide insight into the stabilization and transport properties of k π -skyrmions and support their potential use in future spintronic applications.