Regensburg 2010 – scientific programme

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MA: Fachverband Magnetismus

MA 11: FS: Topological Defects in Electronic Systems (with TT)

MA 11.5: Topical Talk

Tuesday, March 23, 2010, 11:45–12:15, H20

Skyrmion lattice in MnSi — •Achim Rosch — Institute of Theoretical Physics, University of Cologne, 50937 Cologne, Germany

A magnetic skyrmion is a topologically stable vortex-like spin configuration. Similarly to a vortex lattice of a superconductor, a lattice of skyrmion lines is found [1] in the metallic magnet MnSi in a small magnetic field for a small range of temperatures. This state of matter is stabilized by weak spin-orbit interactions and thermal fluctuations. The topological winding number of the skyrmions implies that moving electrons pick up a Berry phase which leads to a characteristic contribution to the Hall constant [2] and an efficient coupling of currents to the magnetic structure. We therefore also investigate how spin-torque effects can lead to modifications of the magnetic structure when electric currents are applied.

[1] S. Mühlbauer, B. Binz, F. Jonietz, C. Pfleiderer, A. Rosch, A. Neubauer, R. Georgii, P. Böni, Science 323, 915 (2009).

[2] A. Neubauer, C. Pfleiderer, B. Binz, A. Rosch, R. Ritz, P. G. Niklowitz, P. Böni , Phys. Rev. Lett. 102, 186602 (2009).