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

In a collaboration with colleagues at Johannes Gutenberg-Universit├Ąt Mainz, Uppsala Universitet, and Christian-Albrechts-Universit├Ąt 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 […]

Role of nonlinear anisotropic damping in the magnetization dynamics of topological solitons

Reference: J.-V. Kim, Phys. Rev. B 92, 014418 (2015). By including the Rashba interaction into a model for nonlinear feedback damping, I studied how the dynamics of magnetic solitons, such as domain walls, vortices, and skyrmions, might be affected by additional torques resulting from this damping. This work has just appeared in Physical Review B. […]

Current-driven asymmetric magnetization switching in perpendicularly magnetized CoFeB/MgO heterostructures

Reference: J. Torrejon et al., Phys. Rev. B 91, 214434 (2015). By using analytical theory and micromagnetics simulations, we helped to explain experimental observations of an asymmetry in current-induced magnetization switching in ultrathin CoFeB/MgO films. This work has just appeared in Physical Review B. Last modified 30/06/15