Thermodynamics of the BCS-BEC crossover
arXiv:cond-mat/0608282 · doi:10.1103/PhysRevA.75.023610
Abstract
We present a self-consistent theory for the thermodynamics of the BCS-BEC crossover in the normal and superfluid phase which is both conserving and gapless. It is based on the variational many-body formalism developed by Luttinger and Ward and by DeDominicis and Martin. Truncating the exact functional for the entropy to that obtained within a ladder approximation, the resulting self-consistent integral equations for the normal and anomalous Green functions are solved numerically for arbitrary coupling. The critical temperature, the equation of state and the entropy are determined as a function of the dimensionless parameter , which controls the crossover from the BCS-regime of extended pairs to the BEC-regime of tightly bound molecules. The tightly bound pairs turn out to be described by a Popov-type approximation for a dilute, repulsive Bose gas. Even though our approximation does not capture the critical behaviour near the continuous superfluid transition, our results provide a consistent picture for the complete crossover thermodynamics which compare well with recent numerical and field-theoretic approaches at the unitarity point.
published version
References in corpus (13)
- Vortices and Superfluidity in a Strongly Interacting Fermi Gas
- Observation of Bose-Einstein Condensation of Molecules
- Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
- Crossover from a molecular Bose-Einstein condensate to a degenerate Fermi gas
- Weakly bound dimers of fermionic atoms
- Critical Temperature and Thermodynamics of Attractive Fermions at Unitarity
- Epsilon expansion for a Fermi gas at infinite scattering length
- Equation of state of a superfluid Fermi gas in the BCS-BEC crossover
- Temperature of a trapped unitary Fermi gas at finite entropy
- Broad versus narrow Fano-Feshbach resonances in the BCS-BEC crossover with trapped Fermi atom
- A two-channel R-matrix analysis of magnetic field induced Feshbach resonances
- Conserving Gapless Mean-Field Theory for Weakly Interacting Bose Gases
- Conserving and gapless approximations for the composite bosons in terms of the constituent fermions
Cited by in corpus (31)
- Many-Body Physics with Ultracold Gases
- Theory of ultracold Fermi gases
- Phase diagram of a two-component Fermi gas with resonant interactions
- Quantum degenerate two-species Fermi-Fermi mixture coexisting with a Bose-Einstein condensate
- Quantum Fluctuations in the Superfluid State of the BCS-BEC Crossover
- Determination of the Superfluid Gap in Atomic Fermi Gases by Quasiparticle Spectroscopy
- Bragg spectroscopy of a strongly interacting Fermi gas
- Universal Properties of the Ultra-Cold Fermi Gas
- Normal state of highly polarized Fermi gases: Full many-body treatment
- Critical velocity for superfluid flow across the BEC-BCS crossover
- Measurement of the Entropy and Critical Temperature of a Strongly Interacting Fermi Gas
- Theory of RF-spectroscopy of strongly interacting Fermions
- Thermodynamic Measurements in a Strongly Interacting Fermi Gas
- Large-N expansion for unitary superfluid Fermi gases
- Critical Temperature Curve in the BEC-BCS Crossover
- Flow Equations for the BCS-BEC Crossover
- Particle-hole fluctuations in the BCS-BEC Crossover
- Comparative study of strong coupling theories of a trapped Fermi gas at unitarity
- Renormalisation Flow and Universality for Ultracold Fermionic Atoms
- Thermodynamics of a trapped unitary Fermi gas
- Three-body scattering from nonperturbative flow equations
- Renormalization of the BCS-BEC crossover by order parameter fluctuations
- Multi-component strongly attractive Fermi gas: a color superconductor in a one-dimensional harmonic trap
- BCS-BEC crossover in dense relativistic matter: Collective excitations
- Critical Behaviour in Trapped Strongly Interacting Fermi Gases
- Low-momentum ring diagrams of neutron matter at and near the unitary limit
- Generalized Galitskii approach for the vertex function of a Fermi gas with resonant interaction
- -dimensions Dirac fermions BEC-BCS cross-over thermodynamics
- Adiabatic cooling of a tunable Bose-Fermi mixture in an optical lattice
- Unitary Fermi gas in the epsilon expansion
- Statistical mechanics of a Feshbach coupled Bose-Fermi gas in an optical lattice