Fast Atom Diffraction of H and He from a LiF(001) surface: Semi-Quantum Approach

M.S. GRAVIELLE; J.E. MIRAGLIA; G.A. BOCAN

Toledo

Conferencia; XXIX International Conference on Photonic, Electronic and Atomic Collisions; 2015

ICPEAC

For fast atom diffraction (FAD) from crystal surfaces we introduce a distorted wave method, based on the semi-quantum approach of the quantum evolution operator, in order to improve the description of rainboweffects given by the Surface Eikonal (SE) model. The theory, named Surface Initial Value Representation (SIVR) approximation, is applied to H and He atoms colliding with a LiF(001) surface, using pair-wise additiveand DFT?derived potentials. The SIVR approach provides a very good representation of the experimental distributions, even in the angular region around classical rainbow angles where the SE method diverges. In addition, the influence of the incident wave-packet is analyzed.