A Fourier-space approach for the computation of magnetostatic interactions between arbitrarily shaped particles

A new formalism has been developed to describe the magnetostatic energy associated with particles of arbitrary shape and magnetization state. The formalism relies on a Fourier space description of the particle shape, through the so-called shape amplitude, which can be used to obtain explicit expressions for the demagnetization tensor field, magnetic field, magnetic induction and magnetostatic energy of a particle for a given magnetization state. Moreover, the interaction energy between particles, located at arbitrary positions in space, which may have different shapes and magnetization states can also be computed. These results may contribute to a deeper understanding of magnetostatic coupling in nanostructures and of the role of shape anisotropy.