Molecular Bose-Einstein condensation in a Bose gas with a wide Feshbach resonance at finite temperatures

Journal Article · Mon Feb 15 00:00:00 EST 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.023613· OSTI ID:21408286

Zengqiang, Yu; Lan, Yin ^[1]

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1. School of Physics, Peking University, Beijing 100871 (China)

Bose-Einstein condensation (BEC) of Feshbach molecules in a homogeneous Bose gas is studied at finite temperatures in a single-channel mean-field approach where the Hartree-Fock energy and pairing gap are determined self-consistently. In the molecular-BEC state, the atomic excitation is gapped and the molecular excitation is gapless. The binding energy of Feshbach molecules is shifted from the vacuum value by many-body effects. When the scattering length a{sub s} of the atoms is negative, the system is subject to mechanical collapse due to negative compressibility. The system is stable in most regions with positive scattering lengths. However, at low temperatures near the resonance, the molecular-BEC state vanishes, and the coherent mixture of atomic and molecular BEC is subject to mechanical collapse.

• OSTI ID: 21408286
• Journal Information: Physical Review. A, Vol. 81, Issue 2; Other Information: DOI: 10.1103/PhysRevA.81.023613; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
BINDING ENERGY
BOSE-EINSTEIN CONDENSATION
BOSE-EINSTEIN GAS
COMPRESSIBILITY
EXCITATION
HARTREE-FOCK METHOD
MANY-BODY PROBLEM
MEAN-FIELD THEORY
MIXTURES
MOLECULES
RESONANCE
SCATTERING LENGTHS
TEMPERATURE RANGE 0065-0273 K
APPROXIMATIONS
CALCULATION METHODS
DIMENSIONS
DISPERSIONS
ENERGY
ENERGY-LEVEL TRANSITIONS
LENGTH
MECHANICAL PROPERTIES
TEMPERATURE RANGE