Magnetic particle-antiparticle creation and annihilation

Abstract

A fundamental property of particles and antiparticles, such as electrons and positrons, is their ability to annihilate one another. Similar behavior is predicted for magnetic solitons -- localized spin textures that can be distinguished by their topological index $Q$. Theoretically, magnetic topological solitons with opposite values of $Q$, such as skyrmions and their antiparticles -- antiskyrmions -- are expected to be able to merge continuously and to annihilate. However, experimental verification of such particle-antiparticle pair production and annihilation processes has been lacking. Here, we report the creation and annihilation of skyrmion-antiskyrmion pairs in an exceptionally thin film of the cubic chiral magnet B20-type FeGe observed using transmission electron microscopy. Our observations are highly reproducible and are fully consistent with micromagnetic simulations. Our findings provide a new platform for fundamental studies of particles and antiparticles based on magnetic solids and open new perspectives for practical applications of thin films of isotropic chiral magnets.

16 pages, 14 figures