Spin-orbit torque-driven skyrmion dynamics revealed by time-resolved X-ray microscopy

TLDR

Magnetic skyrmions are topologically protected spin textures promising for high‑density, low‑power spintronic devices, yet their ultrafast real‑space dynamics remain experimentally elusive despite extensive study. We investigate the nanosecond dynamics of a 100‑nm skyrmion under current pulses using time‑resolved pump‑probe soft X‑ray imaging. The study employs time‑resolved pump‑probe soft X‑ray microscopy to capture skyrmion dynamics during current pulse application. Distinct dynamic excitation states of skyrmions, induced by current‑driven spin‑orbit torques, can be tuned by varying torque magnitude, demonstrating nanosecond‑scale controllability that opens avenues for ultrafast skyrmionic applications.

Abstract

Magnetic skyrmions are topologically-protected spin textures with attractive properties suitable for high-density and low-power spintronic device applications. Much effort has been dedicated to understanding the dynamical behaviours of the magnetic skyrmions. However, experimental observation of the ultrafast dynamics of this chiral magnetic texture in real space, which is the hallmark of its quasiparticle nature, has so far remained elusive. Here, we report nanosecond-dynamics of a 100 nm-size magnetic skyrmion during a current pulse application, using a time-resolved pump-probe soft X-ray imaging technique. We demonstrate that distinct dynamic excitation states of magnetic skyrmions, triggered by current-induced spin-orbit torques, can be reliably tuned by changing the magnitude of spin-orbit torques. Our findings show that the dynamics of magnetic skyrmions can be controlled by the spin-orbit torque on the nanosecond time scale, which points to exciting opportunities for ultrafast and novel skyrmionic applications in the future.