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

TL;DR

This study uses time-resolved X-ray microscopy to observe and control nanosecond-scale dynamics of magnetic skyrmions driven by spin-orbit torques, revealing their potential for ultrafast spintronic devices.

Contribution

First direct real-space observation of ultrafast skyrmion dynamics induced by spin-orbit torques using time-resolved X-ray imaging.

Findings

Skyrmion dynamics can be tuned by changing spin-orbit torque magnitude.

Magnetic skyrmions respond to current pulses on nanosecond timescales.

Distinct dynamic states of skyrmions are reliably triggered and observed.

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.