| 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 3He 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, measurements of the Hall effect suggest the survival of a topological winding akin that of skyrmions in a non-Fermi liquid regime at high pressures, where neutrons scattering suggests the absence of long-range magnetic order. |
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