Phase diagram of a two-component Fermi gas with resonant interactions

Abstract

The pairing of fermions is at the heart of superconductivity and superfluidity. The recent experimental realization of strongly interacting atomic Fermi gases has opened a new, controllable way to study novel forms of pairing and superfluidity. A major controversial issue has been the stability of superfluidity against an imbalance between the two spin components when the fermions interact resonantly. Here we present the phase diagram of a spin-polarized Fermi gas of ${}^6$Li atoms at unitarity, mapping out the superfluid phase versus temperature and density imbalance. Using tomographic techniques, we reveal spatial discontinuities in the spin polarization, the signature of a first-order superfluid-to-normal phase transition, which disappears at a tricritical point where the nature of the phase transition changes from first-order to second-order. At zero temperature, there is a quantum phase transition from a fully-paired superfluid to a partially-polarized normal gas. These observations and the implementation of an in situ ideal gas thermometer provide quantitative tests of theoretical calculations on the stability of resonant superfluidity.

8 pages, 8 figures, reference added, typo corrected

References in corpus (13)

• Theory of ultracold Fermi gases
• Observation of Phase Separation in a Strongly-Interacting Imbalanced Fermi Gas
• Thermodynamics of the BCS-BEC 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
• Critical Temperature and Thermodynamics of Attractive Fermions at Unitarity
• Pairing without Superfluidity: The Ground State of an Imbalanced Fermi Mixture
• Measurement of the Entropy and Critical Temperature of a Strongly Interacting Fermi Gas
• Generic Phase Diagram of Fermion Superfluids with Population Imbalance
• Surface Tension in Unitary Fermi Gases with Population Imbalance
• Zero Temperature Thermodynamics of Asymmetric Fermi Gases at Unitarity
• Phase diagram of a polarized Fermi gas across a Feshbach resonance in a potential trap

Cited by in corpus (35)

• Many-Body Physics with Ultracold Gases
• Generalized Virial Theorem and Pressure Relation for a strongly correlated Fermi gas
• Room-Temperature Superfluidity in Graphene Bilayers
• Determination of the Superfluid Gap in Atomic Fermi Gases by Quasiparticle Spectroscopy
• Normal state of highly polarized Fermi gases: Full many-body treatment
• Antiferromagnetic Order of Strongly Interacting Fermions in a Trap: Real-Space Dynamical Mean-Field Analysis
• Realization of a strongly interacting Bose-Fermi mixture from a two-component Fermi gas
• Renormalization Group Theory for the Imbalanced Fermi Gas
• Heavy-Light Fermion Mixtures at Unitarity
• Determination of the Equation of State of a Two-Component Fermi Gas at Unitarity
• Collisional Properties of a Polarized Fermi Gas with Resonant Interactions
• FFLO state in 1, 2, and 3 dimensional optical lattices combined with a non-uniform background potential
• Thermodynamics of a trapped unitary Fermi gas
• The effect of population imbalance on the Berezinskii-Kosterlitz-Thouless phase transition in a superfluid Fermi gas
• Quantum phase diagram of fermion mixtures with population imbalance in one-dimensional optical lattices
• The role of interactions in spin-polarised atomic Fermi gases at unitarity
• Probing spatial spin correlations of ultracold gases by quantum noise spectroscopy
• The axial anomaly and the phases of dense QCD
• Itinerant Ferromagnetism in an Atom Trap
• Finite-size and confinement effects in spin-polarized trapped Fermi gases
• Induced P-wave superfluidity within full energy-momentum dependent Eliashberg approximation in asymmetric dilute Fermi gases
• Density profiles of polarized Fermi gases confined in harmonic traps
• Noise correlations of the ultra-cold Fermi gas in an optical lattice
• Normal-Superfluid Interface for Polarized Fermion Gases
• Monte Carlo studies of extensions of the Blume-Emery-Griffiths model
• The Trapped Polarized Fermi Gas at Unitarity
• Unitary polarized Fermi gas under adiabatic rotation
• Mott Phase in Polarized Two-component Atomic Fermi Lattice Gas:A Playground for S=1/2 Heisenberg Model in Magnetic Field
• Polarized superfluids near their tricritical point
• Temperature Effects in a Fermi Gas with Population Imbalance
• Phase diagram of imbalanced fermions in optical lattices
• Three-dimensional correlated-fermion phase separation from analysis of the geometric mean of the individual susceptibilities
• Phase diagram of imbalanced strongly interacting fermions on a one-dimensional optical lattice
• Equation of State and Phases of Polarized Unitary Fermi Gas
• Superfluid-density of the ultra-cold Fermi gas in optical lattices