Physics Colloquium, Hocine Khemliche, ISMO, Orsay France: "Fast atom-surface scattering in the quantum regime"

Abstract:

Ions and atoms at keV energies are ideal probes for surface characterization because they offer, compared to electrons or photons, a much higher sensitivity to the terminating layer. Due to the smallness of their de Broglie wavelength, these are utterly treated as classical particles. At very grazing incidence, their energy in the direction normal to the surface can be as low as few meV, thus reducing drastically the likelihood for inelastic interaction. In these conditions, where nothing seems to happen, these objects may exhibit a quantum character, in total conflict with common “scientific wisdom”.

This quantum scattering regime reveals itself through a diffraction (interference) pattern, which is the most spectacular manifestation of the wave nature of matter. In our presentation, we will explain the conditions of this quantum scattering and show examples of it application for both fundamental and applied research.