DIFFRACTION OF SWIFT ATOMS AFTER GRAZING SCATTERING FROM CRYSTAL SURFACES

M.S. GRAVIELLE; G. A. BOCAN; C. RÍOS RUBIANO; R. DÍEZ MUIÑO

Caen

Conferencia; 22nd International Symposium on Ion-Atom Collisions; 2011

ISIAC

New experiments under grazing scattering conditions [1,2] have shown interference effects for atoms in the keV energy range, where classical mechanics was supposed to be adequate. This unexpected diffraction phenomenon was found to be very sensitive to the projectile-surface interaction, which opens the way for a method to probe surface potentials with high accuracy.The first experimental evidences of this effect were reported for insulator surfaces for which the presence of a band gap strongly suppresses inelastic electronic processes, favoring the conservation of quantum coherence. However, fast atom diffraction has recently been observed at metallic materials as well, although electron excitations were supposed to smudge interference signatures for these surfaces. In this work we make use of a distorted-wave model - the surfaceeikonalapproximation [3] - to study diffraction effects for metal surfaces [4], focusing on the role played by the projectile-surface interaction.References[1] A. Schüller, S. Wethekam and H. Winter, Phys. Rev. Lett. 98, 016103 (2007).[2] P. Rousseau, H. Khemliche, A. G. Borisov, and P. Roncin, Phys. Rev. Lett. 98, 016104 (2007).[3] M.S. Gravielle and J.E. Miraglia, Phys. Rev. A. 78, 022901 (2008).[4] M. S. Gravielle, G. A. Bocan, and R. Díez Muiño, Phys. Rev. A 82, 052904 (2010).