Measurement of the interaction strength in a Bose-Fermi mixture with {sup 87}Rb and {sup 40}K

Journal Article · Sun Aug 01 04:00:00 EDT 2004 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.70.021601· OSTI ID:20645834

Goldwin, J; Inouye, S; Olsen, M L; Newman, B; DePaola, B D; Jin, D S ^[1]

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1. JILA, National Institute of Standards and Technology, University of Colorado, Boulder, Colorado 80309 (United States)

A quantum degenerate, dilute gas mixture of bosonic and fermionic atoms was produced using {sup 87}Rb and {sup 40}K. The onset of degeneracy was confirmed by observing the spatial distribution of the gases after time-of-flight expansion. Furthermore, the magnitude of the interspecies scattering length between the doubly spin-polarized states of {sup 87}Rb and {sup 40}K, a{sub RbK}, was determined from cross-dimensional thermal relaxation. The uncertainty in this collision measurement was greatly reduced by taking the ratio of interspecies and intraspecies relaxation rates, yielding a{sub RbK}=250{+-}30 a{sub 0}, which is a lower value than what was reported in [M. Modugno et al., Phys. Rev. A 68, 043626 (2003)]. Using the value for a{sub RbK} reported here, current T=0 theory would predict a threshold for mechanical instability that is inconsistent with the experimentally observed onset for sudden loss of fermions in [G. Modugno et al., Science 297, 2240 (2002)].

• OSTI ID: 20645834
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 70; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOM-ATOM COLLISIONS
ATOMS
BOSONS
COUPLING
EXPANSION
FERMIONS
GASES
INSTABILITY
MIXTURES
POTASSIUM 40
RELAXATION
RUBIDIUM 87
SCATTERING LENGTHS
SPATIAL DISTRIBUTION
SPIN
TIME-OF-FLIGHT METHOD