Quantifying the topology of magnetic skyrmions in three dimensions

        The Paper of the Day article describes the use of soft x-ray laminography to obtain a quantitative 3D analysis of the spin texture of a magnetic skyrmion in a multilayered disk. The topological skyrmion number was computed directly from the 3D data, showing a depth-dependent evolution of the radial profile. Estimates of the micromagnetic energy densities, including exchange, DMI, and anisotropy, suggest that the changes in topological profile are related to nonuniform competing energetic interactions across the depth of the sample. The chirality of the skyrmion was found to be constant across the depth, indicating a positive Néel-type profile. This work establishes soft x-ray laminography as a powerful technique for probing the 3D spin textures of magnetic systems at the nanoscale, providing a foundation for nanoscale metrology for future spintronic devices using topology as a design parameter.