Self-consistent electric field-induced dipole interaction of colloidal spheres, cubes, rods, and dumbbells

Abstract

When calculating the interaction between electric field-induced dipoles, the dipole moments are often taken to be equal to their polarizability multiplied by the external electric field. However, this approach is not exact, since it does not take into account the fact that particles with a dipole moment affect the local electric field experienced by other particles. In this work, we employ the Coupled Dipole Method to calculate the electric-field-induced dipole pair interaction self-consistently: that is, we take into account many-body effects on the individual induced dipole moments. We calculate interactions of particles with nonvanishing dimensions by splitting them up into self-consistently inducible “chunks” of polarizable matter. For point dipoles, spheres, cubes, rods, and dumbbells, we discuss the differences and commonalities between our self-consistent approach and the aforementioned approach of pre-assigning dipole moments to either the point dipoles or, in the case of spatially extended particles, to the chunks making up the particle.