Multipole interaction of polarized single-domain particles

The multipole moments and multipole-multipole interactions of uniformly polarized particles have been calculated based on the fundamental theory of electrostatics. As the polarization of the particles is uniform, only surface charges are considered. The polarization may have its origin in magnetization or ferroelectricity or be an intrinsic property of molecules. It is demonstrated that, depending on the geometry of the particles, the higher order interactions can be comparable to or even stronger than the dipole-dipole interaction. The higher order moments give rise to an additional energy contribution in arrays of close packed polarized nanoparticles. The influence of particle aspect ratios as well as array periodicity is discussed.