Abstract
We observe high-resolution diffraction patterns of a thermal-energy helium atom beam reflected from a microstructured surface grating at grazing incidence. The grating consists of -wide Cr strips patterned on a quartz substrate and has a periodicity of . Fully resolved diffraction peaks up to the seventh order are observed at grazing angles up to . With changes in de Broglie wavelength or grazing angle the relative diffraction intensities show significant variations which shed light on the nature of the atom-surface interaction potential. The observations are explained in terms of quantum reflection at the long-range attractive Casimir–van der Waals potential.
- Received 31 January 2008
DOI:https://doi.org/10.1103/PhysRevA.78.010902
©2008 American Physical Society