Local density of states of atoms interacting with finite-bandwidth surfaces: Spin-statistics effects

Abstract

The density of states on atoms interacting with solid surfaces is a required physical quantity for the understanding of processes related to scanning tunneling and photoemission spectroscopy, single-atom conductance, and emission and scattering of atoms from surfaces. In this work, we present a model calculation that allows including the localized aspects of atomic interactions and the extended features of the surface, together with alternative treatments of the Coulomb repulsion terms in the atom site. The effects of the spin fluctuation statistics treated up to a second order in the atom-surface coupling term are especially explored in this case. This approximation is comparatively analyzed with the exact results available in a model system of four levels and then used in the description of hydrogen interacting with an Al surface. Effects due to finite bandwidth and energy dependence of the local surface density of states are discussed.