Control of the dynamics of coupled atomic-molecular Bose-Einstein condensates: Modified Gross-Pitaevskii approach

Journal Article · Thu Oct 15 04:00:00 EDT 2009 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.80.043618· OSTI ID:21316455

Gupta, Moumita; Dastidar, Krishna Rai ^[1]

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1. Department of Spectroscopy, Indian Association for the Cultivation of Science, Kolkata 700032 (India)

We study the dynamics of the atomic and molecular Bose-Einstein condensates (BECs) of {sup 87}Rb in a spherically symmetric trap coupled by stimulated Raman photoassociation process. Considering the higher order nonlinearity in the atom-atom interaction we analyze the dynamics of the system using coupled modified Gross-Pitaevskii (MGP) equations and compare it with mean-field coupled Gross-Pitaevskii (GP) dynamics. Considerable differences in the dynamics are obtained in these two approaches at large scattering length, i.e., for large values of peak-gas parameter x{sub pk}{>=}10{sup -3}. We show how the dynamics of the coupled system is affected when the atom-molecule and molecule-molecule interactions are considered together with the atom-atom interaction and also when the strengths of these three interactions are increased. The effect of detuning on the efficiency of conversion of atomic fractions into molecules is demonstrated and the feasibility of maximum molecular BEC formation by varying the Raman detuning parameter at different values of time is explored. Thus by varying the Raman detuning and the scattering length for atom-atom interaction one can control the dynamics of the coupled atomic-molecular BEC system. We have also solved coupled Gross-Pitaevskii equations for atomic to molecular condensate formation through magnetic Feshbach resonance in a BEC of {sup 85}Rb. We found similar features for oscillations between atomic and molecular condensates noted in previous theoretical study and obtained fairly good agreement with the evolution of total atomic condensate observed experimentally.

• OSTI ID: 21316455
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 4 Vol. 80; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
BOSE-EINSTEIN CONDENSATION
COMPARATIVE EVALUATIONS
CONDENSATES
CONTROL
CONVERSION
EFFICIENCY
EVOLUTION
MEAN-FIELD THEORY
MOLECULE-MOLECULE COLLISIONS
MOLECULES
NONLINEAR PROBLEMS
PHOTOCHEMISTRY
RADIATION PRESSURE
RAMAN EFFECT
RUBIDIUM
RUBIDIUM 85
RUBIDIUM 87
SCATTERING LENGTHS