Three-dimensional spin configuration of ferromagnetic nanocubes

We have systematically investigated three-dimensional spin configurations in ferromagnetic nanocubes using micromagnetic simulation with variation of cube geometry. For thin cuboids, a spin configuration exhibits a four-domain Landau state with a magnetic vortex structure at the center as in the case of a thin film square. For a thick cube, a complex spin configuration with an S-type cylindrically asymmetric vortex having two cores on a pair of surfaces while a leaf-like and a C-type states are observed on the other two pairs of cube surfaces. Competition between the geometrical symmetry and magnetic energy minimization condition in ferromagnetic nanocubes leads to the complex spin structure with a spontaneously broken symmetry.