Output coupling and flow of a dilute Bose-Einstein condensate

TL;DR

This paper models the behavior of a dilute Bose-Einstein condensate using the Gross-Pitaevskii equation, exploring eigenstates, output coupling, and flow dynamics with gravity and constrictions.

Contribution

It introduces a comprehensive simulation of condensate output coupling and flow, including effects of gravity and interactions with second condensates.

Findings

Output pulse shape matches experimental observations

Eigenmode excitation and separation demonstrated

Flow dynamics under gravity modeled successfully

Abstract

We solve the Gross-Pitaevskii equation to model the behaviour of a weakly-interacting Bose condensate. Solutions are presented for the eigenstates in one- and two-dimensional harmonic traps. We include the effect of gravity and coupling to a second condensate to simulate an output coupler for Bose condensed atoms, and find that the output pulse shape is in qualitative agreement with experiment. We also model flow under gravity through a constriction, demonstrating excitation and separation of eigenmodes in the condensate.