Tilted chiral spin textures in confined nanostructures with in-plane magnetic anisotropy

We demonstrate that nanoconfinement effects and in-plane magnetic anisotropy (IMA) can lead to tilted chiral spin textures in magnetic nanostructures, based on the analysis and simulation of theoretical models of micromagnetism. The tilted skyrmions are induced in confined nanoscale magnets with IMA under perpendicular magnetic fields. The chiral magnetic structures depend significantly on the size of the nanostructures. A controlled string of periodic skyrmion states emerges within the central magnetic domain wall, which can be tuned by the steady magnetic fields and the size of the nanostructures. Nontrivial topological states with noninteger topological charges are achieved by tuning the magnetic fields or the sizes of the nanostructures. Importantly, the periodic switching between the trivial and the nontrivial topological configurations is realized using an alternating magnetic field. Our study reveals an important mechanism for controlling novel skyrmion states via nanoconfinement effects and the IMA in magnetic nanostructures, and also provides a new approach for the development of magnetic field-modulated spin nanodevices.