Recalculations of Long-Range van der Waals Potentials

The long-range van der Waals forces between a particle and a conducting wall, and between two polarizable particles are calculated including contributions from both electric and magnetic polarizabilities. The techniques applied here of using quantum zero-point energy or semiclassical force and energy expressions have been used previously only for the case of purely electrically polarizable particles. A particle with an induced magnetic dipole moment may be repelled from a conducting wall while one with an induced electric dipole moment is attracted. The general retarded two-particle van der Waals potential obtained is identical with that found by Feinberg and Sucher from dispersion-theoretic calculations.