Niels Bohr Lecture by Prof. Achim Rosch

Dr. Achim Rosch, Institut fuer Theoretische Physik, Universitaet zu Koeln

Magnetic whirls in chiral magnets: skyrmions and monopoles

Abstract: In chiral magnets and small magnetic fields lattices of magnetic whirls, so-called skyrmions, can be stabilized. These skyrmions can be manipulated by electric currents which are 5-6 orders of magnitude smaller than conventionally needed for the manipulation of magnetic structures. The very efficient coupling of the magnetic structure to currents is governed by Berry phases, which can be described by effective "emergent" electromagnetic fields. The topological quantization of the the skyrmions thereby leads to a quantization of the emergent magnetic flux. A change of topology has to occur by singular magnetic configurations [3] which act as sources and sinks of the emergent magnetic flux. Thereby they can be viewed as emergent magnetic monopols.

• Wednesday, October 23, 2013 at 15:15 in Aud. 3 at HCØ.

Brief CV:

• Dr. rer. nat, Universität Karlsruhe(1997) ("Heavy Particle in a Fermionic Bath");
  Dipl.-Phys. Universität Karlsruhe (1994)
• Postdoc at Rutgers University, NJ, USA (1998-2000)
• Head of a Emmy-Noether Junior research group (DFG) (2000-2003) within the group of Prof. Wölfle in Karlsruhe
• summer 2002: visiting professor (Vertretungsprofessur) at the LMU Munich
• starting 1/04: full professor at the University to Cologne
• 2006-2012: spokesperson of the Collaborative Research Center SFB 608
• 2012: University prize of the University of Cologne
• since 2012: spokesperson of the key profile area "Quantum Matter and Materials" of the University of Cologne
• 2013: Gottfried Wilhelm Leibniz Prize of the DPG (with Roderich Moessner)
• editor for The European Physical Journal B