Skyrmion Hall effect revealed by direct time-resolved X-ray microscopy

TitleSkyrmion Hall effect revealed by direct time-resolved X-ray microscopy
Publication TypeJournal Article
Year of Publication2017
AuthorsLitzius, K, Lemesh, I, Krueger, B, Bassirian, P, Caretta, L, Richter, K, Buettner, F, Sato, K, Tretiakov, OA, Foerster, J, Reeve, RM, Weigand, M, Bykova, L, Stoll, H, Schuetz, G, Beach, GSD, Klaeui, M
JournalNature Physics
Pagination170 - 175
Date Published2017/02//
ISBN Number1745-2473
Keywordsdriven, dynamics, magnetic skyrmions, order, real-space observation, weak ferromagnetism

Magnetic skyrmions are promising candidates for future spintronic applications such as skyrmion racetrack memories and logic devices. They exhibit exotic and complex dynamics governed by topology and are less influenced by defects, such as edge roughness, than conventionally used domain walls. In particular, their non-zero topological charge leads to a predicted 'skyrmion Hall effect', in which current-driven skyrmions acquire a transverse velocity component analogous to charged particles in the conventional Hall effect. Here, we use nanoscale pump-probe imaging to reveal the real-time dynamics of skyrmions driven by current-induced spin-orbit torques. We find that skyrmions move at a well-defined angle Theta(SkH) that can exceed 300 with respect to the current flow, but in contrast to conventional theoretical expectations, Theta(SkH) increases linearly with velocity up to at least 100 ms(-1). We qualitatively explain our observation based on internal mode excitations in combination with a field-like spin-orbit torque, showing that one must go beyond the usual rigid skyrmion description to understand the dynamics.

Short TitleNat. Phys.