Quasiclassical approximation for the resonant Kapitza–Dirac scattering

Abstract

In a momentum space, the resonant Kapitza–Dirac effect is described by the difference Schrödinger equation the step of which is the two-photon recoil momentum. For the interferometry of a multipath atom, the case of intense counter-propagating waves is of interest, when the number of generated momenta can reach to some tens. After that, in an intermediate stage of calculations, the discrete momentum distribution is regarded as a continuous one, and the Taylor expansion is applicable to it. This approximation preserves the spectrum of a diffraction well, in particular, the formation of a pair of almost monopulse states from the initial Gaussian distribution.