Real-Space Observation of a Transformation from Antiskyrmion to Skyrmion by Lorentz TEM

Lorentz transmission electron microscopy (TEM) is extensively used to investigate nanometer-scale magnetic textures owing to its high spatial resolution. A conventional Lorentz TEM at the Fresnel mode can effectively obtain the information about in-plane magnetizations as well as their changes under various external stimuli. Recently, magnetic skyrmions [1] and antiskyrmions [2] have drawn particular attention due to their nanometer size and topological stability, and hence have potential applications as information carriers in magnetic storages. Skyrmions and antiskyrmions are vortex-like topological particles and anti-particles with topological charges -1 and +1 [3], respectively. To apply skyrmions and antiskyrmions to spintronics, we need to understand and control them.