QUANTUM SCATTERING FROM DISORDERED SURFACES

A projected continuum formulation for time-independent quantum scattering from a continuum of channels is presented and applied to atomic scattering from disordered surfaces. Projecting out the channel continua gives rise to explicitly constructed optical potentials for the coherently diffracted scattering amplitudes, while the continuum diffuse scattering contribution is obtained in terms of these wave functions. Numerical application is made to atomic scattering from weakly corrugated disordered surfaces, for which a truncated set of coupled equations can be used within which the theory is shown to be unitary. The occurrence of a new phenomenon of disorder-induced sticking on rigid surfaces is demonstrated and comparison with phonon-induced sticking is made. These new disorder-induced sticking processes are shown to have very different energy dependence than phonon-induced sticking, with strong resonant sticking and oscillatory behavior seen at low incident energies.