Dresden 2017 – wissenschaftliches Programm
MA 47.2: Vortrag
Donnerstag, 23. März 2017, 09:45–10:00, HSZ 04
Crossover between mechanisms of skyrmion annihilation in a racetrack — •Pavel Bessarab1, Igor Lobanov2, Gideon Müller3, Filipp Rybakov4, Nikolai Kiselev3, Stefan Blügel3, Lars Bergqvist5, and Anna Delin5 — 1University of Iceland, Reykjavík, Iceland — 2ITMO University, St. Petersburg, Russia — 3Forschungszentrum Jülich, Jülich, Germany — 4Institute of Metal Physics, Ekaterinburg, Russia — 5KTH Royal Institute of Technology, Kista, Sweden
Theoretical calculations of thermal stability of skyrmions in a PdFe bilayer strip on an Ir(111) substrate are presented. The lifetime of a skyrmion at a given temperature is identified using harmonic transition state theory for spins . The energy barriers are obtained from minimum energy paths (MEPs) for skyrmion annihilation and pre-exponential factors are estimated from the curvature of the energy surface. The MEP calculations  revealed two mechanisms of skyrmion annihilation in the strip: escape through the boundary and radial collapse at the interior. At low external fields, the escape mechanism prevails, but a crossover field exists, above which the collapse mechanism becomes dominant, defining the skyrmion stability. This analysis provides a deeper understanding of skyrmion formation and stability and helps develop ways to control magnetic skyrmions in novel devices.
 P.F. Bessarab, V.M. Uzdin, H. Jónsson, Phys. Rev. B, 85, 184409 (2012).
 P.F. Bessarab, V.M. Uzdin, H. Jónsson, Comput. Phys. Commun., 196, 335 (2015).