Quantum theory of the scattering of helium atoms from adsorbates

Abstract

The van der Waals interaction between an atom and an adsorbate consists of the usual two-body direct interaction as well as three-body interactions from the image force and an interference effect. The three-body interactions are caused by the presence of the surface and render the resulting potential anisotropic even when the adsorbate is spherically symmetrical. Expressions for the leading coefficients of the van der Waals forces and the corresponding reference-plane positions are given in terms of the polarizabilities of the atom, the adsorbate and the substrate. A theory of atomic scattering from a single adsorbate is given and numerical results for the total cross-sections of the He–Xe/Ag system are presented.