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Title: Self-consistent theory of atomic Fermi gases with a Feshbach resonance at the superfluid transition

Abstract

A self-consistent theory is derived to describe the BCS-Bose-Einstein-condensate crossover for a strongly interacting Fermi gas with a Feshbach resonance. In the theory the fluctuation of the dressed molecules, consisting of both preformed Cooper pairs and 'bare' Feshbach molecules, has been included within a self-consistent T-matrix approximation, beyond the Nozieres and Schmitt-Rink strategy considered by Ohashi and Griffin. The resulting self-consistent equations are solved numerically to investigate the normal-state properties of the crossover at various resonance widths. It is found that the superfluid transition temperature T{sub c} increases monotonically at all widths as the effective interaction between atoms becomes more attractive. Furthermore, a residue factor Z{sub m} of the molecule's Green function and a complex effective mass have been determined to characterize the fraction and lifetime of Feshbach molecules at T{sub c}. Our many-body calculations of Z{sub m} agree qualitatively well with recent measurments of the gas of {sup 6}Li atoms near the broad resonance at 834 G. The crossover from narrow to broad resonances has also been studied.

Authors:
;  [1]
  1. ARC Centre of Excellence for Quantum-Atom Optics, Department of Physics, University of Queensland, Brisbane, Queensland 4072 (Australia)
Publication Date:
OSTI Identifier:
20786350
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 72; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevA.72.063613; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; APPROXIMATIONS; ATOMS; BCS THEORY; BOSE-EINSTEIN CONDENSATION; COOPER PAIRS; EFFECTIVE MASS; FERMI GAS; FERMIONS; FLUCTUATIONS; GREEN FUNCTION; LIFETIME; LITHIUM; LITHIUM 6; MANY-BODY PROBLEM; MOLECULES; RESONANCE; S MATRIX; SUPERFLUIDITY; TRANSITION TEMPERATURE

Citation Formats

Liu Xiaji, and Hu Hui. Self-consistent theory of atomic Fermi gases with a Feshbach resonance at the superfluid transition. United States: N. p., 2005. Web. doi:10.1103/PHYSREVA.72.0.
Liu Xiaji, & Hu Hui. Self-consistent theory of atomic Fermi gases with a Feshbach resonance at the superfluid transition. United States. doi:10.1103/PHYSREVA.72.0.
Liu Xiaji, and Hu Hui. Thu . "Self-consistent theory of atomic Fermi gases with a Feshbach resonance at the superfluid transition". United States. doi:10.1103/PHYSREVA.72.0.
@article{osti_20786350,
title = {Self-consistent theory of atomic Fermi gases with a Feshbach resonance at the superfluid transition},
author = {Liu Xiaji and Hu Hui},
abstractNote = {A self-consistent theory is derived to describe the BCS-Bose-Einstein-condensate crossover for a strongly interacting Fermi gas with a Feshbach resonance. In the theory the fluctuation of the dressed molecules, consisting of both preformed Cooper pairs and 'bare' Feshbach molecules, has been included within a self-consistent T-matrix approximation, beyond the Nozieres and Schmitt-Rink strategy considered by Ohashi and Griffin. The resulting self-consistent equations are solved numerically to investigate the normal-state properties of the crossover at various resonance widths. It is found that the superfluid transition temperature T{sub c} increases monotonically at all widths as the effective interaction between atoms becomes more attractive. Furthermore, a residue factor Z{sub m} of the molecule's Green function and a complex effective mass have been determined to characterize the fraction and lifetime of Feshbach molecules at T{sub c}. Our many-body calculations of Z{sub m} agree qualitatively well with recent measurments of the gas of {sup 6}Li atoms near the broad resonance at 834 G. The crossover from narrow to broad resonances has also been studied.},
doi = {10.1103/PHYSREVA.72.0},
journal = {Physical Review. A},
number = 6,
volume = 72,
place = {United States},
year = {Thu Dec 15 00:00:00 EST 2005},
month = {Thu Dec 15 00:00:00 EST 2005}
}