Interactions of He atoms with Xe plated graphite: unified treatment of scattering and adsorbate dynamics based on method of coupled channels

Abstract

Interactions of He atoms with surfaces have been in the focus of surface scientists for more than seventy years. Depending on the types of the studied problems, and on the algorithms available for their assessment, the accuracy of model calculations aiming at the interpretations of the various aspects of He-atom scattering and dynamics in the adsorbed phase have greatly varied during that period. In this article, we describe the application of a numerical algorithm based on the coupled-channel method that proves very accurate in the calculations of eigen-states and eigen-energies of He atoms interacting with strongly corrugated surfaces. The algorithm is applied to compute diffraction spectra characteristic of thermal energy He-atom scattering from a monolayer of Xe atoms adsorbed on (0 0 0 1) surface of graphite, and the thermodynamical quantities describing a quasi-two-dimensional gas of He atoms adsorbed on the same surface. The usefulness of the developed approach is illustrated in comparisons of the theoretical results with the available experimental data.