Abstract
We report coherent reflection of thermal He atom beams from various microscopically rough surfaces at grazing incidence. For a sufficiently small normal component of the incident wave vector of the atom the reflection probability is found to be a function of only. This behavior is explained by quantum reflection at the attractive branch of the Casimir–van der Waals interaction potential. For larger values of the overall reflection probability decreases rapidly and is found to also depend on the parallel component of the wave vector. The material specific dependence for this classic reflection at the repulsive branch of the potential is discussed in terms of an averaging out of the surface roughness under grazing incidence conditions.
- Received 20 November 2009
DOI:https://doi.org/10.1103/PhysRevLett.105.133203
© 2010 The American Physical Society