Correlation effects in image states for atoms confined in a spherical cavity within a conductor

Abstract

In this work we study theoretically one and two-electron atoms confined in a spherical cavity within a conductor. The interaction between the charged particles and the surface is described by a spherical image potential which takes into account each particle-surface interaction together with inter-particle correlation terms coming from surface polarization. Numerical evaluation of the wave functions with the generalized Sturmian method, for one and two-electron atoms, is presented. In the oneelectron case, for R → ∞, analytical solutions of the modified Schrödinger equation are derived. These one-electron energies and states enable us to interpret the one and two-electron atomic eigenfunctions structure and evolution of the energy spectra as a function of the confinement radius. The contribution of each term of the spherical image potential is analysed. When compared to the corresponding unconfined systems, the level structure and the charge density distributions are drastically changed. On top of the usual central Coulomb-like states, new Coulomb-like surface states appear. Their mix depends on the cavity radius and gives rise to subtle avoided crossings.