Ne atom scattering from Ir(111) under nearly classical conditions

摘要

Measurements of Ne atom scattering from a clean and ordered Ir(111) surface are shown under conditions in which the scattering is nearly classical. The only quantum mechanical manifestation is a small elastic specular diffraction intensity. The energy-resolved intensity spectra exhibit only a single broad peak attributed to multiple phonon excitations. The multiphonon peak is well explained by classical scattering theory. It is shown that the multiphonon peak can mimic the behavior of a single-phonon dispersion curve, however, measurements at different incident energies can be used to identify this false dispersion curve.