Figure 1: Spin textures in chiral helimagnets.

Besides flat helices (a), chiral helimagnets like Cu₂OSeO₃ manifest radially symmetric topological solitons like skyrmions (b) or half-skyrmions (c), where the local order parameter (sectioned arrows) forms a double-twisted core, tracing out the whole (b) or half (c) of the Bloch sphere. (d) Parallel skyrmions can form densely packed lattices in two spatial dimensions. In a, the colouring of the sectioned arrows tracks the direction of the magnetization in the plane of rotation, while in (b–d) it tracks the longitudinal magnetization. (e) Quantitative first-principles calculations predict that the ferrimagnetic order in Cu₂OSeO₃ is locally altered by the multi-sublattice structure, leading to weak antiferromagnetism (depicted by orange arrowheads). (f) The skyrmion texture is locally composed of these three-dimensional canted spin patterns. Thus, the weak antiferromagnetic order itself is modulated along with the primary ferrimagnetic twisting shown in b.