Multiphonon processes in atom-surface scattering

Helium-atom time-of-flight spectra taken at 69-meV incident energy in scattering from Pt(111) show energy-loss peaks that cannot be assigned to one-phonon transitions, but are qualitatively explained by simple formulas for the multiphonon processes in the classical limit. This assignment is supported by trajectory-approximation calculations that correctly reproduce the experimentally determined density of phonon states of Pt(111).

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Corrrections and comments

• In the Abstract's last line, replace "density of states" by "density of phonon states". (The Abstract on this page is already corrected.)
• In Eq. (1), replace E by K in the numerator on the right hand side.
• In Eq. (4), N₀ should be 1/4 of the value given (in the next line). This will make N normalized to 1 if the energy transfer can have all values. In reality, the energy loss cannot be greater than E_i + D, where D is the well depth. Thus the formula given for N₀ is only approximate.
• The "full Trajectory Approximation" used in this paper is also called the Exponentiated Born Approximation (EBA).
• In Eq. (6), multiply the right hand side by 2. In other words, there should not be a 2 in the denominator.