Ultracold thermalization of {sup 7}Li and {sup 87}Rb

Journal Article · Thu Nov 15 04:00:00 EST 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.76.052704· OSTI ID:21028011

Marzok, C; Deh, B; Courteille, Ph W; Zimmermann, C ^[1]

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1. Physikalisches Institut, Eberhard-Karls-Universitaet Tuebingen, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)

We report on measurements of cross-species thermalization inside a magnetically trapped spin-polarized mixture of {sup 87}Rb and {sup 7}Li atoms with both atoms in their respective low-field-seeking magnetic substates |F=2,m{sub F}=2>. Measurement of the thermalization velocity in the ultracold regime below 10 {mu}K allows for the derivation of the absolute value of the pure triplet s-wave scattering length governing the interaction. We find |a{sub 7,87}|=(59{+-}19)a{sub B}. We propose to study both species in the condensed regime to derive the sign of a{sub 7,87}. In this context, we present numerical solutions to the coupled Gross-Pitaevskii equation based on the hypothesis of a positive sign. According to the simulations, phase separation of the Li and Rb |2,2> clouds occurs along with a mean-field stabilization allowing for larger atom numbers of condensed {sup 7}Li atoms before collapse sets in. Observation of this mean-field stabilization would directly fix the sign of a{sub 7,87}. We discuss our results in the light of this proposal.

• OSTI ID: 21028011
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 76; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
BOSE-EINSTEIN CONDENSATION
EQUATIONS
HYPOTHESIS
INTERACTIONS
LITHIUM 7
MEAN-FIELD THEORY
MIXTURES
NUMERICAL SOLUTION
PHOTON-ATOM COLLISIONS
RUBIDIUM 87
S WAVES
SCATTERING LENGTHS
SIMULATION
SPIN ORIENTATION
STABILIZATION
TEMPERATURE RANGE 0000-0013 K
THERMALIZATION
TRAPPING
VELOCITY