Energy states of a hydrogenic atom placed between two metal slabs

Abstract

We have derived expressions for the self-energy of a hydrogenic atom placed in the cavity formed by two semi-infinite metal slabs. The excitations of the metal surfaces are described in terms of the surface plasmon modes and the atom is assumed to interact with these modes. The self-energies are obtained for the 10S and 14S excited states of the atom. The earlier calculations of the self-energy are based on the dipolar approximation but we show in this paper that when the gap size is sufficiently small, the multipolar interactions can exceed the dipolar contribution. We consider the case when the atom is placed at the center of the gap and obtain the variations in the self-energy when the gap size is varied.