Quantum features in the scattering of atoms from an optical standing wave

We consider the scattering of an atom as it passes through a classical standing wave, without neglecting the center-of-mass kinetic energy. In the large detuning limit we show that this may be modeled as a nonlinear pendulum. In the quantum description fractional revivals of the initial state occur. These revivals are manifest as nonclassical peaks in the distribution of momentum orthogonal to the direction of beam propagation. This quantum scattering could be achieved with cooled well-collimated beams.