Finite temperature phase diagram of a spin-polarized ultracold Fermi gas in a highly elongated harmonic trap

Abstract

We investigate the finite temperature properties of an ultracold atomic Fermi gas with spin population imbalance in a highly elongated harmonic trap. Previous studies at zero temperature showed that the gas stays in an exotic spatially inhomogeneous Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superfluid state at the trap center; while moving to the edge, the system changes into either a non-polarized Bardeen-Cooper-Schriffer superfluid ($P<P_c$) or a fully polarized normal gas ($P>P_c$), depending on the smallness of the spin polarization $P$, relative to a critical value $P_c$. In this work, we show how these two phase-separation phases evolve with increasing temperature, and thereby construct a finite temperature phase diagram. For typical interactions, we find that the exotic FFLO phase survives below one-tenth of Fermi degeneracy temperature, which seems to be accessible in the current experiment. The density profile, equation of state, and specific heat of the polarized system have been calculated and discussed in detail. Our results are useful for the on-going experiment at Rice University on the search for FFLO states in quasi-one-dimensional polarized Fermi gases.

9 pages and 8 figures; Published version in Phys. Rev. A

References in corpus (24)

• Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
• Observation of Phase Separation in a Strongly-Interacting Imbalanced Fermi Gas
• Molecular Probe of Pairing in the BEC-BCS Crossover
• Direct Observation of the Superfluid Phase Transition in Ultracold Fermi Gases
• Deformation of a Trapped Fermi Gas with Unequal Spin Populations
• Normal state of a polarized Fermi gas at unitarity
• Phase diagram of a strongly interacting polarized Fermi gas in one dimension
• Pairing without Superfluidity: The Ground State of an Imbalanced Fermi Mixture
• Pairing states of a polarized Fermi gas trapped in a one-dimensional optical lattice
• Quasi-one-dimensional polarized Fermi superfluids
• Phase diagram of a cold polarized Fermi gas
• Mean field phase diagrams of imbalanced Fermi gases near a Feshbach resonance
• Two-species fermion mixtures with population imbalance
• Phase Transitions and Pairing Signature in Strongly Attractive Fermi Atomic Gases
• Density-Matrix Renormalization Group Study of Trapped Imbalanced Fermi Condensates
• Generic Phase Diagram of Fermion Superfluids with Population Imbalance
• Exact Numerical Study of Pair Formation with Imbalanced Fermion Populations
• Surface Tension in Unitary Fermi Gases with Population Imbalance
• Zero Temperature Thermodynamics of Asymmetric Fermi Gases at Unitarity
• BCS-BEC crossover in an asymmetric two-component Fermi gas
• Mean field thermodynamics of a spin-polarized spherically trapped Fermi gas at unitarity
• Microscopic Structure of a Vortex Line in a Superfluid Fermi Gas
• Phase diagram of a polarized Fermi gas across a Feshbach resonance in a potential trap
• BCS-BEC crossover and quantum phase transition for 6Li and 40K atoms across Feshbach resonance

Cited by in corpus (22)

• Exact quantum Monte Carlo study of one dimensional trapped fermions with attractive contact interactions
• Matrix product ansatz for Fermi fields in one dimension
• Spectral signatures of the Fulde-Ferrell-Larkin-Ovchinnikov order parameter in one-dimensional optical lattices
• Probing the FFLO phase by double occupancy modulation spectroscopy
• Signature of the FFLO phase in the collective modes of a trapped ultracold Fermi gas
• Confinement-induced resonance in quasi-one-dimensional systems under transversely anisotropic confinement
• Finite temperature QMC study of the one-dimensional polarized Fermi gas
• Soliton-induced Majorana fermions in a one-dimensional atomic topological superfluid
• Virial expansion for a strongly correlated Fermi gas with imbalanced spin populations
• Ground states and dynamics of population-imbalanced Fermi condensates in one dimension
• Impurity probe of topological superfluid in one-dimensional spin-orbit coupled atomic Fermi gases
• Interferometric probe of paired states
• Unconventional pairing in one-dimensional systems of a few mass-imbalanced ultracold fermions
• Critical phenomena in one dimension from a Bethe ansatz perspective
• Superfluid density and Berezinskii-Kosterlitz-Thouless transition of a spin-orbit coupled Fulde-Ferrell superfluid
• Quantum Coherent States of Interacting Bose-Fermi Mixtures in One Dimension
• Dynamical generation of solitons in one-dimensional Fermi superfluids with and without spin-orbit coupling
• Phase separations induced by a trapping potential in one-dimensional fermionic systems as a source of core-shell structures
• Protocol to engineer Fulde-Ferrell-Larkin-Ovchinnikov states in a cold Fermi gas
• Transport of Spin and Mass at Normal-Superfluid Interfaces in the Unitary Fermi Gas
• Hartree-Fock-Bogoliubov theory of trapped one-dimensional imbalanced Fermi systems
• Structures and proximity effects of inhomogeneous population-imbalanced Fermi gases with pairing interactions