Quantum Theory of Electron Stimulated Desorption: Nonadiabatic Corrections

Nonadiabatic corrections to the scattering formalism for the description of electron stimulated desorption developed previously are investigated. It turns out that the cross-section for the desorption of ions derived earlier in the Born-Oppenheimer approximation remains essentially unaffected by these corrections (nonadiabatic effects being taken into account with sufficient accuracy in terms of the imaginary part of the BO potential for the ions). The cross-section for the desorption of reneutralized ions, however, which vanishes in BOA becomes nonzero. In semiclassical approximation the expression for the cross-section agrees with the result proposed earlier by Menzel and Gomer. The connection of the formalism with the Landau-Zener theory of nonadiabatic transitions is briefly discussed.