  Superpositions of spin helices can yield topological spin textures, such as
two-dimensional vortices and skyrmions, and three-dimensional hedgehogs. Their
topological nature and spatial dimensionality depend on the number and relative
directions of the constituent helices. This allows mutual transformation
between the topological spin textures by controlling the spatial anisotropy.
Here we theoretically study the effect of anisotropy in the magnetic
interactions for an effective spin model for chiral magnetic metals. By
variational calculations for both cases with triple and quadruple
superpositions, we find that the hedgehog lattices, which are stable in the
isotropic case, are deformed by the anisotropy, and eventually changed into
other spin textures with reduced dimension, such as helices and vortices. We
also clarify the changes of topological properties by tracing the real-space
positions of magnetic monopoles and antimonopoles as well as the emergent
magnetic field generated by the noncoplanar spin textures. Our results suggest
possible control of the topological spin textures, e.g., by uniaxial pressure
and chemical substitution in chiral materials.
