A Mutual Demagnetizing Tensor for N-Body Magnetic Field Modeling

We introduce a mutual demagnetizing tensor for calculating the demagnetizing field in multiple magnetic bodies. Algorithms for magnetic simulations dealing with interactive n-bodies usually treat the simulation domain as a single non-homogeneous body with alternating magnetic and non-magnetic regions. Doing so minimizes the number of variables used in the field calculations, but the extra computation and storage requirements become very large. Our approach not only reduces memory consumption but also shows a gain in performance for cases involving field calculation in patterned films. We have verified our results by performing simulation of periodic dots of similar size arranged in grids of various formats.