Theoretical study of current-induced domain wall motion in magnetic nanotubes with azimuthal domains
Jérôme Hurst, A. De Riz, Michal Staňo, Jean-Christophe Toussaint, Olivier Fruchart, D. Gusakova
Abstract
We report a theoretical overview of the magnetic domain wall behavior under an electric current in infinitely long nanotubes with azimuthal magnetization, combining the one-dimensional analytic model and micromagnetic simulations. We highlight effects that, besides spin-transfer torques already largely understood in flat strips, arise specifically in the tubular geometry: the \OE{}rsted field and curvature-induced magnetic anisotropy resulting both from the exchange interaction and material growth. Depending on both the geometry of the tube and the strength of the azimuthal anisotropy, Bloch or N\'eel walls arise at rest, resulting in two regimes of motion largely dominated by either spin-transfer torques or the \OE{}rsted field. We determine the Walker breakdown current in all cases, and highlight the most suitable parameters to achieve high domain wall speed.