Atom Interference using microfabricated structures

Abstract

Atom density profile arising in the atomic beam after passing through the one or two microfabricated structures (MS) is considered. Two limiting cases the beam with large and small angular divergence are considered. An equivalence of the considerations based on the Fresnel-Kirchhoff theory of diffraction and on the atomic recoil-effect is established. Higher order gratings' profiles produced in the collinear beam owing to the atomic Talbot effect are calculated. For an atomic beam with large angular divergence, two regimes of atoms' scattering off the MS, classical and quantum, are analyzed. For classical scattering from two MSs, the atomic density periodic modulation focusses at the echo points owing to the shadow effect. Elaborated simple geometric interpretation of the echo-effect. Dephasing-rephasing processes induced by two MSs having rational ratio of their periods are fully classified. Positions and profiles of the higher order gratings are calculated. Gratings' deformations caused by the quantum scattering are included. In this case, corresponding to the atomic Talbot-Lau effect, for a distance between fields equal to 1/n part of the Talbot distance, one compresses n times the grating caused by the shadow effect.