A Coupled Multipole Expansion—Finite Element Approach for Dynamic Micromagnetic Modeling

This paper presents a 3-D dynamic micromagnetic numerical procedure, which efficiently computes the magnetostatic field by approximating the contributions of far magnetic dipoles with a multipole expansion technique. This approach is coupled to a finite element spatial reconstructor of the effective field, which leads to the reduction of the second order derivative in the exchange term. The procedure is tested focusing on the influence of the multipole expansion approximation on numerical accuracy and efficiency.