Fast atom diffraction of H and He from a LiF(001) surface: semi-quantum approach

29th International Conference on Photonic, Electronic, and Atomic Collisions

Gravielle, M.S.^1 ; Miraglia, J.E.^1 ; Bocan, G.A.^2

Institute de Astronomía y Física Del Espacio (IAFE, CONICET-UBA), Buenos Aires, Argentina^1

Centro Atómico Bariloche, CONICET, S.C. de Bariloche, Río Negro, Argentina^2

关键词: Angular regions;    Crystal surfaces;    Distorted wave methods;    Fast atom diffractions;    Initial value representation;    Quantum approach;    Quantum evolution;    Rainbow effects;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/635/3/032006/pdf
DOI  :  10.1088/1742-6596/635/3/032006

来源: IOP

【 摘 要 】

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 rainbow effects 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 additive and 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.