He-LiF surface potential from fast atom diffraction under grazing incidence

TL;DR

This paper investigates the atom-surface interaction by analyzing fast atom diffraction patterns from a LiF surface, using DFT calculations and the surface eikonal approximation to understand scattering behavior.

Contribution

It introduces a combined approach of DFT-derived potentials and the surface eikonal approximation for modeling grazing atom diffraction.

Findings

Accurate potential obtained from DFT including polarization and surface relaxation.

Analysis of diffraction spectra dependence on incident energies.

Determination of the model's applicability range.

Abstract

Diffraction patterns produced by grazing scattering of fast atoms from insulator surfaces are used to examine the atom-surface interaction. The method is applied to He atoms colliding with a LiF(001) surface along axial crystallographic channels. The projectile-surface potential is obtained from an accurate DFT calculation, which includes polarization and surface relaxation. For the description of the collision process we employ the surface eikonal approximation, which takes into account quantum interference between different projectile paths. The dependence of projectile spectra on the parallel and perpendicular incident energies is experimentally and theoretically analyzed, determining the range of applicability of the proposed model.