Path sampling for lifetimes of metastable magnetic skyrmions and direct comparison with Kramers’ method

Our recent study on the lifetime of magnetic skyrmions, led by Louise Desplat, has just appeared as a Rapid Communication in Physical Review B. We studied the issue of thermal stability theoretically using two distinct methods. The first involves a generalisation of Kramer’s framework to multidimensional phase spaces due to Langer, while the second is […]

Trochoidal dynamics and pair generation in skyrmion and antiskyrmion dynamics driven by spin-orbit torques

In a collaboration with colleagues at Johannes Gutenberg-Universität Mainz, Uppsala Universitet, and Christian-Albrechts-Universität zu Kiel, we have shown theoretically that skyrmions and antiskyrmions can behave very differently under spin-orbit torques. One key finding is that antiskyrmions can undergo trochoidal motion, which is analogous to Walker breakdown in domain wall dynamics. This threshold defines a speed […]

Current-driven skyrmion dynamics in disordered films

Reference: J.-V. Kim and M.-W. Yoo, Appl. Phys. Lett. 110, 132404 (2017). We studied how current-driven skyrmion motion in ultrathin films is affected by disorder. We modelled the disorder by assuming a grain structure, where the local perpendicular anisotropy fluctuates from grain to grain. We find that the velocity versus current curves are reminiscent of […]

A skyrmion-based spin-torque nano-oscillator

Reference: F. Garcia-Sanchez et al., New J. Phys. 18, 075011 (2016). We show how inhomogeneous spin polarizers in the form of vortices can result in self-sustained gyration of skyrmions in magnetic nanopillars. We suggest that such dynamics could be useful for skyrmion-based spin-torque nano-oscillators. This work has just appeared in the New Journal of Physics. […]