We show that diffraction oscillations in elastic electron-atom scattering can be quantitatively accounted for semiclassically in terms of path interferences. The quantum scattering amplitude is expressed as a topological sum over classical and pseudoclassical paths, containing only information on the classical dynamics. The sum is shown to converge rapidly. The validity of the semiclassical theory of potential scattering is analyzed in terms of the angular-momentum dependence of the classical action for the radial motion.

• Received 14 March 1994

DOI:https://doi.org/10.1103/PhysRevA.51.1248