Observation of Skyrmions in Magnetic Materials

Abstract

Experimentally, skyrmion spin textures are observed in various magnetic systems with distinctive characteristics. In this chapter, some typical material environments, i.e. (1) non-centrosymmetric ferromagnets, (2) centrosymmetric ferromagnets with uniaxial anisotropy and (3) surface/interface of ferromagnetic monolayers, are introduced for realising skyrmion spin textures. (1) and (3) are systems with broken space-inversion symmetry, and thus, the Dzyaloshinskii–Moriya interaction is active and serves as a key source for stabilising skyrmion spin textures. For (2), in contrast, the breaking of space-inversion symmetry is not relevant, but an interplay between the dipole–dipole interaction and magnetic anisotropies is important for the realisation of magnetic skyrmions. In all cases, the typical size of a magnetic skyrmion ranges from sub-micrometre to nanometre, which implies that specific experimental techniques are required to identify the emergence of skyrmion spin textures directly.