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TT: Fachverband Tiefe Temperaturen
TT 19: Poster Session: Correlated Electrons 1
TT 19.45: Poster
Montag, 20. März 2017, 15:00–19:00, P2-EG
Topological domain walls in helimagnets — •Laura Köhler1, Jan Müller2, Achim Rosch2, Peggy Schönherr3, Dennis Meier3,4, and Markus Garst1 — 1Institut für Theoretische Physik, Technische Universität Dresden, 01062 Dresden, Germany — 2Institut für Theoretische Physik, Universität zu Köln, 50937 Cologne, Germany — 3Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland — 4Department of Materials Science and Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway
A magnetic helix arises in chiral magnetic materials with a wavelength set by the spin-orbit coupling. Using micromagnetic simulations and comparing to experimental studies on surfaces of FeGe, we show that domain walls of such helimagnetic order are distinctly different from ferromagnets and rather similar to grain boundaries of liquid crystals. Three types of domain walls are realized depending on the relative domain orientation: a curvature wall, a zig-zag disclination wall and a dislocation wall. Disclinations are vortex defects in the helix axis orientation, and they can be combined to form dislocations. We discuss the topological skyrmion charge associated with these defects, and we demonstrate that domain walls of helimagnetic order can carry a finite topological charge on average. As a consequence, they can be manipulated by spin currents and contribute to a topological Hall effect.