Unitarity-limited elastic collision rate in a harmonically trapped Fermi gas

Journal Article · Tue Jul 01 04:00:00 EDT 2003 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.68.011603· OSTI ID:20639853

Gehm, M E; Hemmer, S L; O'Hara, K M; Thomas, J E ^[1]

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1. Physics Department, Duke University, Durham, North Carolina 27708-0305, USA (United States)

We derive the elastic collision rate for a harmonically trapped Fermi gas in the extreme unitarity limit where the s-wave scattering cross section is {sigma}(k)=4{pi}/k{sup 2}, with ({Dirac_h}/2{pi})k the relative momentum. The collision rate is given in the form {gamma}={gamma} I(T/T{sub F})--the product of a universal collision rate {gamma}=k{sub B}T{sub F}/(6{pi}({Dirac_h}/2{pi})) and a dimensionless function of the ratio of the temperature T to the Fermi temperature T{sub F}. We find that I has a peak value of {approx_equal}4.6 at T/T{sub F}{approx_equal}0.4, I{approx_equal}82 (T/T{sub F}){sup 2} for T/T{sub F}{<=}0.15, and I{approx_equal}2(T{sub F}/T){sup 2} for T/T{sub F}>1.5. We estimate the collision rate for recent experiments on a strongly-interacting degenerate Fermi gas of atoms.

• OSTI ID: 20639853
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 68; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
ATOMS
CROSS SECTIONS
FERMI GAS
FERMIONS
S WAVES
SCATTERING
TRAPPING
UNITARITY