CLASSICAL SINGULARITIES IN CHAOTIC ATOM-SURFACE SCATTERING

In this paper we show that the diffraction condition for the scatterin g of atoms from surfaces leads to the appearance of a distinct type of classical singularity. Moreover, it is also shown that the onset of c lassical trapping or classical chaos is closely related to the bifurca tion set of the diffraction-order function around the surface points p resenting the rainbow effect. As an illustration of this dynamic, appl ication to the scattering of He atoms by the stepped Cu(115) surface i s presented using both a hard corrugated one-dimensional wall and a so ft corrugated Morse potential.