LASER-INDUCED FORCES NEAR A METALLIC SURFACE

The purpose of this paper is a theoretical study of forces induced by a laser beam on nonresonant cold atoms in the vicinity of a metallic surface. We use the same quantum electrodynamics formalism to study and compare all the kinds of forces which can occur. In a first step, when no incident light is present, forces are caused by exchanges of virtual photons and we recover the monoatomic Casimir force and the interatomic van der Waals force, modified by surfaces effects; In a second step, a laser beam is present and we calculate the induced gradient force on one atom and the interatomic light-induced force, which is a binding when similar atoms are considered. Laser light creates interference fringes above the metallic surface which induces an energy grating, where individual atoms could be trapped. Then We study the optical binding for various atoms positions in the fringes. We compare these forces near a perfect metallic surface and the same forces in free space.