Physical Review A
Narrowing of interference fringes in diffraction of prepared atoms by standing waves
Artur Mikhailovich Ishkhanyan
Abstract
The influence of the initial-state preparation on the diffraction of atoms in the field of a standing wave is discussed. The solution of the coherent scattering problem for rather general initial conditions involving initial atomic wave-packet splitting in the momentum space is obtained. A different effect of narrowing of the interference fringes of the diffraction pattern caused by secondary interference during the standing-wave scattering is discovered. The effect takes place at a specific type of initial wave-packet splitting involving two translation states whose momenta differ by even photon momenta, corresponding to the same, ground or excited, internal state. It is shown that a higher-order narrowing can be achieved using binomial wave packets. Further, another case that causes an asymmetrically narrowed diffraction is presented. An atomic-beam-splitting technique based on the preparation of atoms by STIRAP is proposed.