Elastic scattering losses from colliding BEC's

TL;DR

This paper investigates elastic scattering losses in colliding Bose-Einstein condensates, analyzing the transition from spontaneous to stimulated scattering and deriving analytical expressions for scattered atom correlations.

Contribution

It provides a detailed study of a model for colliding BECs, including the transition from spontaneous to stimulated scattering and analytical insights into atom correlations.

Findings

Analytical expressions for the density matrix and anomalous density.

Insights into the correlation properties of scattered atoms.

Characterization of the transition from spontaneous to stimulated scattering.

Abstract

Bragg diffraction divides a Bose-Einstein condensate into two overlapping components, moving with respect to each other with high momentum. Elastic collisions between atoms from distinct wave packets can significantly deplete the condensate. Recently Zi\'{n} {\it et al.} (Phys. Rev. Lett. {\bf 94}, 200401 (2005)) have introduced a model of two counter-propagating atomic Gaussian wavepackets incorporating dynamics of the incoherent scattering processes. Here we study the properties of this model in detail, including the nature of the transition from spontaneous to stimulated scattering. Within the first order approximation we derive analytical expressions for the density matrix and anomalous density which provides excellent insight into correlation properties of scattered atoms.