Physics of Curvilinear Magnetism

The modification of magnetic properties in bent thin films is investigated by atomistic model calculation. Compared to mathematical transformation associated with the introduction of curvilinear coordinates, the present bending effects are physical and lead to additional terms in the Hamiltonian. Speci­fically, the bending creates curvature-dependent anisotropy terms and Dzyaloshinski-Moriya inter­actions. Micromagnetic simulations are also conducted on curved rings exhibiting two cases of high and low radial anisotropy. In cases of high anisotropy, spins align along the radial anisotropy direction, while for low anisotropy, the spins tend to align parallel to each other, avoiding alignment along the radial anisotropy direction. This reflects non-collinear spin textures on a flat surface in the presence of Dzyaloshinski-Moriya inter­actions. Our findings are important for the understanding of mechanical deformed magnetic structures, for example thin films in devices and artificial nanostructures.