Multiple scattering of matter waves: an analytic model of the refractive index for atomic and molecular gases

TL;DR

This paper develops an analytic model combining long-range attraction and short-range repulsion to accurately predict the refractive index of matter waves in atomic and molecular gases, aligning well with recent experimental data.

Contribution

It introduces a novel analytic approach integrating WKB and Fraunhofer models to describe matter wave propagation in gases, emphasizing the importance of diffractive effects.

Findings

Model agrees with recent experimental measurements

Diffractive scattering is crucial for the imaginary part of the refractive index

Provides insights into matter wave interactions with dilute gases

Abstract

We present an analytic model of the refractive index for matter waves propagating through atomic or molecular gases. The model, which combines a WKB treatment of the long range attraction with the Fraunhofer model treatment of the short range repulsion, furnishes a refractive index in compelling agreement with recent experiments of Jacquey et al. [Phys. Rev. Lett. 98, 240405 (2007)] on Li atom matter waves passing through dilute noble gases. We show that the diffractive contribution, which arises from scattering by a two dimensional "hard core" of the potential, is essential for obtaining a correct imaginary part of the refractive index.