Pseudo-gap pairing in ultracold Fermi atoms

Abstract

The crossover from a BEC (Bose-Einstein condensation) to a BCS (Bardeen-Cooper-Schrieffer) superfluid in dilute gases of ultracold Fermi atoms creates an ideal environment to enrich our knowledge of strongly correlated many-body systems. These experiments are relevant to a wide range of fields from condensed matter to astrophysics. The nature of pairing in strongly interacting Fermi gases can be readily studied, thus aiding our understanding of related problems in high-T_{c} superconductors, whose mechanism is still under debate. These are not well-understood due to the large interaction parameter. Here, we calculate the dynamical properties of a normal, trapped, and strongly correlated Fermi gas, by developing a quantum cluster expansion. In ultra-cold atomic physics one can measure the elementary excitations, using rf or Bragg spectroscopy. Our calculations for the single-particle spectral function agree with the recent measurements, and clearly demonstrate pseudogap pairing in the strongly interacting regime.

arXiv comment4 pages, 4 figures; add comparison with the JILA pseudogap measurement (Nature Physics); published version in Phys. Rev. Lett

References in corpus (24)

• Angle-resolved photoemission spectroscopy of the cuprate superconductors
• Theory of ultracold Fermi gases
• Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
• Large momentum part of fermions with large scattering length
• Exploring the Thermodynamics of a Universal Fermi Gas
• Using photoemission spectroscopy to probe a strongly interacting Fermi gas
• The BCS-BEC Crossover in a Gas of Fermi Atoms with a Feshbach Resonance
• Deviations from Fermi-liquid behavior above $T_c$ in 2D short coherence length superconductors
• Pseudogap and spectral function from superconducting fluctuations to the bosonic limit
• Bragg spectroscopy of a strongly interacting Fermi gas
• Spectral Functions and rf Response of Ultracold Fermionic Atoms
• Equation of state of a superfluid Fermi gas in the BCS-BEC crossover
• Virial expansion for a strongly correlated Fermi gas
• High temperature expansion applied to fermions near Feshbach resonance
• Measurement of the Entropy and Critical Temperature of a Strongly Interacting Fermi Gas
• Universal thermodynamics of strongly interacting Fermi gases
• Single-particle properties and pseudogap effects in the BCS-BEC crossover regime of an ultracold Fermi gas above Tc
• Superconductivity close to the Mott state: From condensed-matter systems to superfluidity in optical lattices
• Evidence for pairing above Tc from the dispersion in the pseudogap phase of cuprates
• The Finite Temperature Pairing Gap of a Unitary Fermi Gas by Quantum Monte Carlo Calculations
• Probing the Spectral Function Using Momentum Resolved Radio Frequency Spectroscopy in Trapped Fermi Gases
• Universal Short-Distance Structure of the Single-Particle Spectral Function of Dilute Fermi Gases
• Twin peaks in rf spectra of Fermi gases at unitarity
• Bragg Spectroscopy of Cold Atomic Fermi Gases

Cited by in corpus (64)

• Observation of a pairing pseudogap in a two-dimensional Fermi gas
• Comparing and contrasting nuclei and cold atomic gases
• Virial expansion for a strongly correlated Fermi system and its application to ultracold atomic Fermi gases
• Spectral response and contact of the unitary Fermi gas
• Three attractively interacting fermions in a harmonic trap: Exact solution, ferromagnetism, and high-temperature thermodynamics
• Exact few-body results for strongly correlated quantum gases in two dimensions
• Onset of a Pseudogap Regime in Ultracold Fermi Gases
• Universal contact of strongly interacting fermions at finite temperatures
• Pseudogaps in strongly interacting Fermi gases
• Radio-frequency spectroscopy of a strongly interacting spin-orbit coupled Fermi gas
• Superfluid density of states and pseudogap phenomenon in the BCS-BEC crossover regime of a superfluid Fermi gas
• Pair Correlations in the Two-Dimensional Fermi Gas
• Spin susceptibility and fluctuation corrections in the BCS-BEC crossover regime of an ultracold Fermi gas
• Local origin of the pseudogap in the attractive Hubbard model
• Evolution of the Pseudogap in a polarized Fermi gas
• Pairing effects in the non-degenerate limit of the two-dimensional Fermi gas
• Pseudogap temperature and effects of a harmonic trap in the BCS-BEC crossover regime of an ultracold Fermi gas
• 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
• High-temperature limit of the resonant Fermi gas
• Quantitative comparison between theoretical predictions and experimental results for Bragg spectroscopy of a strongly interacting Fermi superfluid
• Probing strongly interacting atomic gases with energetic atoms
• Virial expansion for a strongly correlated Fermi gas with imbalanced spin populations
• Low-dimensional pairing fluctuations and pseudogapped photoemission spectrum in a trapped two-dimensional Fermi gas
• High-temperature expansion for interacting fermions
• High temperature thermodynamics of strongly interacting s-wave and p-wave Fermi gases in a harmonic trap
• Breakdown of the Fermi polaron description near Fermi degeneracy at unitarity
• Universal dynamic structure factor of a strongly correlated Fermi gas
• Hartree shift in unitary Fermi gases
• Excitation properties and effects of mass imbalance in the BCS-BEC crossover regime of an ultracold Fermi gas
• Strong-coupling corrections to spin susceptibility in the BCS-BEC crossover regime of a superfluid Fermi gas
• BCS-BEC crossover at finite temperature in spin-orbit coupled Fermi gases
• Pairing and radio-frequency spectroscopy in two-dimensional Fermi gases
• Sigature of the universal super Efimov Effect: three-body contact in two dimensional Fermi gases
• Local Photoemission Spectra and Effects of Spatial Inhomogeneity in the BCS-BEC Crossover Regime of a Trapped Ultracold Fermi Gas
• Hetero pairing and component-dependent pseudogap phenomena in an ultracold Fermi gas with mass imbalance
• Radio-frequency spectroscopy of weakly bound molecules in spin-orbit coupled atomic Fermi gases
• Momentum-resolved spectroscopy of a Fermi liquid
• Pseudogap phenomenon and effects of population imbalance in the normal state of a unitary Fermi gas
• Coexistence of superfluid gap and pseudogap in the BCS-BEC crossover regime of a trapped Fermi gas below $T_{\mathrm{c}}$
• Formation of magnetic impurities and pair-breaking effect in a superfluid Fermi gas
• Pairing fluctuations and anisotropic pseudogap phenomenon in an ultracold superfluid Fermi gas with plural $p$-wave superfluid phases
• Evolution of Cooper pairs with zero-center-of-mass momentum and their first-order correlation function in a two-dimensional ultracold Fermi gas near the observed Berezinskii-Kosterlitz-Thouless transition
• Thermodynamic Properties of Rashba Spin-Orbit-Coupled Fermi Gas
• Exact Quantum Virial Expansion for the Optical Response of Doped Two-Dimensional Semiconductors
• Strong-Coupling and Finite Temperature Effects on $p$-wave Contacts
• Pseudogap regime of a strongly interacting two-dimensional Fermi gas with and without confinement-induced effect range of interactions
• Dynamic structure factor of a strongly correlated Fermi superfluid within a density functional theory approach
• Low-Dimensional Fluctuations and Pseudogap in Gaudin-Yang Fermi Gases
• Single-particle Excitations and Effects of Hetero-pairing Fluctuations in a Bose-Fermi Mixture with a Feshbach Resonance
• Spectroscopic Bogoliubov features near the unitary limit
• Superfluid/ferromagnet/superfluid junction and $\pi$-phase in a superfluid Fermi gas
• Slow-light probe of Fermi pairing through an atom-molecule dark state
• Many-body theories of density response for a strongly correlated Fermi gas
• Isothermal compressibility and effects of multi-body molecular interactions in a strongly interacting ultracold Fermi gas
• Pseudogap regime of a two-dimensional uniform Fermi gas
• Pseudogap phenomena near the BKT transition of a two-dimensional ultracold Fermi gas in the crossover region
• Specific Heat and Effects of Uniaxial Anisotropy of a $p$-wave Pairing Interaction in a Strongly Interacting Ultracold Fermi Gas
• Pairing fluctuation effects in a strongly coupled color superfluid/superconductor
• Normal-state Properties of a Unitary Bose-Fermi Mixture: A Combined Strong-coupling Approach with Universal Thermodynamics
• Critical pairing fluctuations in the normal state of a superconductor: pseudogap and quasi-particle damping
• Inhomogeneous Pseudogap Phenomenon in the BCS-BEC Crossover Regime of a Trapped Superfluid Fermi Gas
• Theory of Photoemission-type Experiment in the BCS-BEC Crossover Regime of a Superfluid Fermi Gas
• Spin Susceptibility and Strong Coupling Effects in an Ultracold Fermi Gas