Abstract: Magnetic skyrmions in noncentrosymmetric chiral magnets form ordered lattices with a periodicity ranging from 3-100 nm. This length scale lends itself to soft X-ray scattering experiments owing to the large resonant scattering cross-section for 3-D elements, the excellent reciprocal space resolution, and the tunable surface sensitivity. We will present an overview of the capabilities of resonant elastic X-ray scattering (REXS) for the study of magnetic skyrmions, highlighting the following effects:
- Topology: Using circularly polarized light, REXS is capable of accurately determining the topological winding number of a skyrmion. This topology determination principle is a general experimental strategy, applicable to a wide range of topologically ordered magnetic materials.
- Microscopic skyrmion properties: By exploiting the polarization dependence of REXS, we determined the exact surface helicity angles of twisted skyrmions for both left- and right-handed chiral bulk Cu2OSeO3.
- Full 3-D spin structure of skyrmions: Using polarization-dependent REXS, we found a continuous transformation of the skyrmion tubes from pure Néel twisting at the surface to pure Bloch twisting in the bulk over a distance of several hundred nanometers.
- Rotating lattices: In a magnetic field gradient, skyrmions undergo rotation with well-defined dynamics. This provides an effective way of controlling skyrmions in racetrack memory schemes.