BCS-BEC crossover in an asymmetric two-component Fermi gas

Abstract

We discuss the superfluid phase transition of a strongly interacting Fermi gas with unequal (asymmetric) chemical potentials in two pairing hyperfine states, and map out its phase diagram near the BCS-BEC crossover. Our approach includes the fluctuation contributions of {}``preformed Cooper pairs'' to the thermodynamic potential at finite temperature. We show that, below a critical difference in chemical potentials between species, a normal gas is unstable towards the formation of either a finite-momentum paired Fulde-Ferrell-Larkin-Ovchinnikov superconducting phase or a uniform superfluid, depending on the asymmetry and interaction strengths. We determine the value of critical chemical potential mismatch, and find good qualitative agreement with a recent measurement by Zwierlein \textit{et al.} {[}Science \textbf{311}, 492 (2006){]}.

7 pages + 3 figures; To appear in Europhysics Letters

References in corpus (20)

• Vortices and Superfluidity in a Strongly Interacting Fermi Gas
• Pairing and Phase Separation in a Polarized Fermi Gas
• Fermionic Superfluidity with Imbalanced Spin Populations and the Quantum Phase Transition to the Normal State
• Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
• Evidence for Superfluidity in a Resonantly Interacting Fermi Gas
• Inhomogeneous Superconductivity in Condensed Matter and QCD
• Collective excitations of a degenerate gas at the BEC-BCS crossover
• The BCS-BEC Crossover in a Gas of Fermi Atoms with a Feshbach Resonance
• Molecular Probe of Pairing in the BEC-BCS Crossover
• Interior Gap Superfluidity
• Heat Capacity of a Strongly-Interacting Fermi Gas
• BEC-BCS crossover in "magnetized" Feshbach-resonantly paired superfluids
• Phase separation in asymmetrical fermion superfluids
• Asymmetric Two-component Fermion Systems in Strong Coupling
• Equation of state of a superfluid Fermi gas in the BCS-BEC crossover
• Collective modes and ballistic expansion of a Fermi gas in the BCS-BEC crossover
• Superfluid stability in BEC-BCS crossover
• Mean field phase diagrams of imbalanced Fermi gases near a Feshbach resonance
• Temperature of a trapped unitary Fermi gas at finite entropy
• A self-consistent theory of atomic Fermi gases with a Feshbach resonance at the superfluid transition

Cited by in corpus (55)

• The BCS-BEC crossover: From ultra-cold Fermi gases to nuclear systems
• BEC-BCS crossover, phase transitions and phase separation in polarized resonantly-paired superfluids
• Finite temperature phase diagram of a polarised Fermi condensate
• Universal thermodynamics of strongly interacting Fermi gases
• Fluctuations and phase transitions in Larkin-Ovchinnikov liquid crystal states of population-imbalanced resonant Fermi gas
• Fulde-Ferrell-Larkin-Ovchinnikov states in one-dimensional spin-polarized ultracold atomic Fermi gases
• Virial expansion for a strongly correlated Fermi system and its application to ultracold atomic Fermi gases
• Zero Temperature Thermodynamics of Asymmetric Fermi Gases at Unitarity
• Rashba spin-orbit coupled atomic Fermi gases
• Universal contact of strongly interacting fermions at finite temperatures
• Finite temperature phase diagram of a spin-polarized ultracold Fermi gas in a highly elongated harmonic trap
• Superfluidity at the BEC-BCS crossover in two-dimensional Fermi gases with population and mass imbalance
• Pseudogaps in strongly interacting Fermi gases
• Universal thermodynamics of a strongly interacting Fermi gas: theory versus experiment
• Itinerant ferromagnetism in an atomic Fermi gas: Influence of population imbalance
• Mean field thermodynamics of a spin-polarized spherically trapped Fermi gas at unitarity
• Spin susceptibility and fluctuation corrections in the BCS-BEC crossover regime of an ultracold Fermi gas
• Comparative Study of BCS-BEC Crossover Theories above $T_c$: the Nature of the Pseudogap in Ultra-Cold Atomic Fermi Gases
• Evolution of the Pseudogap in a polarized Fermi gas
• Finite Temperature Phase Diagram of a Two-Component Fermi Gas with Density Imbalance
• Static structure factor of a strongly correlated Fermi gas at large momenta
• Uniform spin susceptibility and spin-gap phenomenon in the BCS-BEC crossover regime of an ultracold Fermi gas
• Breakdown of the local density approximation in interacting systems of cold fermions in strongly anisotropic traps
• Polaron Problems in Ultracold Atoms: Role of a Fermi Sea across Different Spatial Dimensions and Quantum Fluctuations of a Bose Medium
• Evaluating the phase diagram of superconductors with asymmetric spin populations
• Quantum liquid-crystal order in resonant atomic gases
• Stoner ferromagnetism of a strongly interacting Fermi gas in the quasirepulsive regime
• Excitation properties and effects of mass imbalance in the BCS-BEC crossover regime of an ultracold Fermi gas
• Superfluid Phase Transitions and Effects of Thermal Pairing Fluctuations in Asymmetric Nuclear Matter
• Polarized Fermi gases at finite temperature in the BCS-BEC crossover
• Strong-coupling corrections to spin susceptibility in the BCS-BEC crossover regime of a superfluid Fermi gas
• Fulde-Ferrell superfluidity in ultracold Fermi gases with Rashba spin-orbit coupling
• Trapped Resonant Fermions above Superfluid Transition Temperature
• Spin-polarized Fermi superfluids as Bose-Fermi mixtures
• Bose-Fermi Pairs in a Mixture and the Luttinger Theorem within a Nozieres-Schmitt-Rink like Approach
• Pseudogap phenomenon and effects of population imbalance in the normal state of a unitary Fermi gas
• Quantum Lifshitz points and fluctuation-induced first-order phase transitions in imbalanced Fermi mixtures
• Dimensional Crossover in a Spin-imbalanced Fermi gas
• Validity of single-channel model for a spin-orbit coupled atomic Fermi gas near Feshbach resonances
• Occupation numbers in strongly polarized Fermi gases and the Luttinger theorem
• Luttinger theorem and imbalanced Fermi systems
• Feasibility of a Fulde-Ferrell-Larkin-Ovchinnikov superfluid Fermi atomic gas
• Josephson effect in an atomic Fulde-Ferrell-Larkin-Ovchinnikov superfluid
• Application of renormalized RPA to polarized Fermi gases
• Beyond Gaussian pair fluctuation theory for strongly interacting Fermi gases
• LOFF and breached pairing with cold atoms
• Fulde-Ferrell pairing instability of a Rashba spin-orbit coupled Fermi gas
• Magnetic properties and strong-coupling corrections in an ultracold Fermi gas with population imbalance
• Quantum Lifshitz points in an altermagnetic metal
• Superfluid phase transition and strong-coupling effects in an ultracold Fermi gas with mass imbalance
• Shear Viscosity of Uniform Fermi Gases with Population Imbalance
• Pair condensation of polarized fermions in the BCS-BEC crossover
• Rabi coupled fermions in the BCS-BEC crossover
• An Effective Series Expansion to the Equation of State of Unitary Fermi Gases
• Spin Susceptibility and Strong Coupling Effects in an Ultracold Fermi Gas