Emergence, Stability and Decay of Skyrmions in Chiral Magnets
Prof. Dr. Christian Pfleiderer, Physik-Department, Technische Universität München
- 07 Jun 2013 11:00
Skyrmions are particle-like configurations of continuous fields named after the English particle physicist Tony Skyrme. Their existence has long been considered in nuclear matter, quantum Hall systems, liquid crystals, superfluid He and ultracold atoms. I will review the emergence, stability and decay of skyrmions as a novel generic property of chiral magnets, where they lead to an emergent electrodynamics with a wide range of practical consequences. Notably, the non-zero topological winding corresponds to precisely one quantum of emergent magnetic flux that mediates an extremely efficient coupling between the conduction electrons and the magnetic properties. In turn, the emergent flux leads to a topological Hall signal, spin transfer torques at ultra-low current densities and emergent electric fields. Additionally skyrmions are characterised by an exceptional stability, which cannot be simply suppressed under large hydrostatic pressures. In fact, one important decay mechanism identified recently are point defects, which may be viewed as quantized magnetic monopoles and antimonopoles, providing sources and sinks of one flux quantum of emergent magnetic flux, respectively.
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