On the influence of resonance photon scattering on atom interference

TL;DR

This paper investigates how resonance photon scattering affects atom interference patterns in a Mach-Zehnder interferometer, showing that the interference visibility depends on the momentum transfer distribution and the scattering location.

Contribution

It provides a theoretical analysis demonstrating the impact of photon-atom scattering on interference visibility, emphasizing the importance of scattering location and momentum transfer in atom interferometry.

Findings

Interference visibility depends on the statistical distribution of transferred momenta.

Photon-atom scattering within the near field influences interference patterns.

The analysis explains the experimental dependence of visibility on the ratio d_p/λ_i.

Abstract

Here, the influence of resonance photon-atom scattering on the atom interference pattern at the exit of a three-grating Mach-Zehnder interferometer is studied. It is assumed that the scattering process does not destroy the atomic wave function describing the state of the atom before the scattering process takes place, but only induces a certain shift and change of its phase. We find that the visibility of the interference strongly depends on the statistical distribution of transferred momenta to the atom during the photon-atom scattering event. This also explains the experimentally observed (Chapman et al 1995 Phys. Rev. Lett. 75 2783) dependence of the visibility on the ratio d_p/\lambda_i = y'_{12} (2\pi/kd\lambda_i), where y'_{12} is distance between the place where the scattering event occurs and the first grating, k is the wave number of the atomic center-of-mass motion, $d$ is the grating constant and \lambda_i is the photon wavelength. Furthermore, it is remarkable that photon-atom scattering events happen experimentally within the Fresnel region, i.e. the near field region, associated with the first grating, which should be taken into account when drawing conclusions about the relevance of "which-way" information for the interference visibility.