Speaker
Description
Magnetic skyrmions, nanoscale chiral spin textures with particle-like behavior, are promising candidates for information storage and unconventional computing due to their robustness and efficient current-driven motion [1-3]. In Ta/CoFeB/MgO multilayers, we investigate the transition of current-driven skyrmion motion from creep, through depinning, to the viscous flow regime driven by a unipolar, pulsed current. By varying current density, pulse width, and frequency, we demonstrate how external stimulation overcomes pinning potentials and guides skyrmions into a regime characterized by linear velocity–current relations, i.e., the viscous flow regime. Additional studies with an alternating, net-zero current drive reveal an exponential increase of the diffusion coefficient with current density, while higher frequencies suppress diffusion following a power-law dependence. These findings provide quantitative insight into controlling skyrmion mobility and diffusion, essential for spintronic device design [4].
[1] G. Beneke et al., Nat. Commun., 15, 8103 (2024).
[2] K. Raab et al., Nat. Commun., 13, 6982 (2022).
[3] K. Everschor-Sitte et al., J. Appl. Phys., 124, 24, 240901 (2018).
[4] L. Dany et al., under preparation.
