https://doi.org/10.1007/s100530050586
Pair correlation function of an inhomogeneous interacting Bose-Einstein condensate
Laboratoire Kastler-Brossel (Laboratoire Kastler
Brossel is a unité de recherche de
l'École Normale Supérieure et de l'Université Pierre et Marie Curie,
associée au CNRS.) ,
CNRS-Laboratoire de Physique Statistique
de l'École Normale Supérieure, 24 rue Lhomond, 75005 Paris, France
Received:
16
December
1999
Published online: 15 October 1999
We calculate the pair correlation function of an interacting Bose gas in a harmonic trap directly via Path Integral Quantum Monte-Carlo simulation for various temperatures and compare the numerical result with simple approximative treatments. Around the critical temperature of Bose-Einstein condensation, a description based on the Hartree-Fock approximation is found to be accurate. At low temperatures the Hartree-Fock approach fails and we use a local density approximation based on the Bogoliubov description for a homogeneous gas. This approximation agrees with the simulation results at low temperatures, where the contribution of the phonon-like modes affects the long range behavior of the correlation function. Further we discuss the relation between the pair correlation and quantities measured in recent experiments.
PACS: 03.75.Fi – Phase coherent atomic ensembles; quantum condensation phenomena (Bose condensation) / 02.70.Lq – Monte Carlo and statistical methods / 05.30.Jp – Boson systems
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999
