Reorientations, relaxations, metastabilities and domains of skyrmion lattices

Abstract

Magnetic skyrmions are nano-sized topologically protected spin textures with particle-like properties. They can form lattices perpendicular to the field of which the orientation with respect to the crystallographic lattice is governed by spin-orbit coupling. By performing small angle neutron scattering measurements in a new way, we investigate the coupling between the crystallographic and skyrmion lattices in both Cu\(_2\)OSeO\(_3\) and the archetype chiral magnet MnSi. The results reveal that the orientation of the skyrmion lattice is primarily determined by the magnetic field direction with respect to the crystallographic lattice. In addition, it is also influenced by the magnetic history that can induce metastable lattices. Kinetic measurements show that these metastable skyrmion lattices may or may not relax to their equilibrium positions under macroscopic relaxation times. Multi-domain lattices can form when several crystallographic orientations as favored by spin-orbit coupling are equivalent.