Dressed-molecules in resonantly-interacting ultracold atomic Fermi gases
arXiv:cond-mat/0603270 · doi:10.1103/PhysRevA.75.023612
Abstract
We present a detailed analysis of the two-channel atom-molecule effective Hamiltonian for an ultracold two-component homogeneous Fermi gas interacting near a Feshbach resonance. We particularly focus on the two-body and many-body properties of the dressed molecules in such a gas. An exact result for the many-body T-matrix of the two-channel theory is derived by both considering coupled vertex equations and the functional integral methods. The field theory incorporates exactly the two-body physics of the Feshbach scattering by means of simple analytical formulas without any fitting parameters. New interesting many-body effects are discussed in the case of narrow resonances. We give also a description of the BEC-BCS crossover above and below T_C. The effects of different approximations for the selfenergy of the dressed molecules are discussed. The single-channel results are derived as a special limit for broad resonances. Moreover, through an analytic analysis of the BEC limit, the relation between the composite boson of the single-channel model and the dressed-molecule of the two-channel model is established.
44 pages, 24 figures
References in corpus (27)
- Vortices and Superfluidity in a Strongly Interacting Fermi Gas
- Pairing and Phase Separation in a Polarized Fermi Gas
- Observation of Bose-Einstein Condensation of Molecules
- Fermionic Superfluidity with Imbalanced Spin Populations and the Quantum Phase Transition to the Normal State
- Crossover from a molecular Bose-Einstein condensate to a degenerate Fermi gas
- Weakly bound dimers of fermionic atoms
- Collective excitations of a degenerate gas at the BEC-BCS crossover
- Molecular Probe of Pairing in the BEC-BCS Crossover
- Confinement induced molecules in a 1D Fermi gas
- Heat Capacity of a Strongly-Interacting Fermi Gas
- Pure Gas of Optically Trapped Molecules Created from Fermionic Atoms
- Observation of molecules produced from a Bose-Einstein condensate
- Kondo effect in quantum dots
- Atom-molecule dark states in a Bose-Einstein condensate
- BCS-BEC crossover at finite temperature in the broken-symmetry phase
- A self-consistent theory of atomic Fermi gases with a Feshbach resonance at the superfluid transition
- Properties of the strongly paired fermionic condensates
- Self-consistent theory for molecular instabilities in a normal degenerate Fermi gas in the BEC-BCS crossover
- Sum Rules and Ward Identities in the Kondo Lattice
- Universality in Phase Transitions for Ultracold Fermionic Atoms
- Sound modes at the BCS-BEC crossover
- Popov approximation for composite bosons in the BCS-BEC crossover
- Dressed Feshbach molecules in the BEC-BCS crossover
- Population of closed-channel molecules in trapped Fermi gases with broad Feshbach resonances
- Simple Mean-Field Theory for a Zero-Temperature Fermi Gas at a Feshbach Resonance
- Feshbach molecules in a one-dimensional Fermi gas
- Fermionic superfluidity with positive scattering length
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- Theory of ultracold Fermi gases
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- Orbital Feshbach Resonance: A "Wide" Narrow Resonance for Higher Transition Temperature Fermi Superfluid
- Anomalous Behavior of Dark States in Quantum Gases of 6Li
- Interacting Preformed Cooper Pairs in Resonant Fermi Gases
- Theory for Bose-Einstein condensation of light in nano-fabricated semiconductor microcavities
- Generalized Galitskii approach for the vertex function of a Fermi gas with resonant interaction
- Evolution of the unitary Bose gas for broad to narrow Feshbach resonances
- Three small systems showing probable room-temperature superconductivity
- Tunable Molecular Interactions Near an Atomic Feshbach Resonance: Stability and Collapse of a Molecular Bose-Einstein Condensate