Like-charge attraction between two identical dielectric spheres in a uniform electric field: a theoretical study via a multiple-image method and an effective-dipole approach

Abstract

A multiple-image method is developed as an accurate numerical approach to calculate the electrostatic interaction between two like-charged dielectric spheres in a uniform electric field. Compared with the effective-dipole approach, the multiple-image method provides more precise numerical results that are in agreement with experimental results. The attractive and repulsive forces can be manipulated by adjusting net charge, relative permittivity, external electric field, and gap size. In the case of two like-charged spheres, both short-range attraction and long-range repulsion are observed under a uniform electric field. A slight decrease of the gap between the spheres leads to a significant increase in the accumulation of unlike charges within the inner localized surfaces of the spheres. This results in a substantial enhancement in the magnitude of the interaction force.