Enhanced critical temperature, pairing fluctuation effects, and BCS-BEC crossover in a two-band Fermi gas
arXiv:1901.11444 · doi:10.1103/PhysRevB.99.180503
Abstract
We study the superfluid critical temperature in a two-band attractive Fermi system with strong pairing fluctuations associated with both interband and intraband couplings. We focus specifically on a configuration where the intraband coupling is varied from weak to strong in a shallow band coupled to a weakly-interacting deeper band. The whole crossover from the Bardeen-Cooper-Schrieffer (BCS) condensation of largely overlapping Cooper pairs to the Bose-Einstein condensation (BEC) of tightly bound molecules is covered by our analysis, which is based on the extension of the Nozières-Schmitt-Rink (NSR) approach to a two-band system. In comparison with the single-band case, we find a strong enhancement of the critical temperature, a significant reduction of the preformed pair region where pseudogap effects are expected, and the entanglement of two kinds of composite bosons in the strong-coupling BEC regime.
7 pages, 6 figures, published version in PRB
References in corpus (51)
- Many-Body Physics with Ultracold Gases
- Theory of ultracold Fermi gases
- Observation of resonance condensation of fermionic atom pairs
- Condensation of Pairs of Fermionic Atoms Near a Feshbach Resonance
- Crossover from a molecular Bose-Einstein condensate to a degenerate Fermi gas
- The BCS-BEC Crossover in a Gas of Fermi Atoms with a Feshbach Resonance
- Field-induced superconducting phase of FeSe in the BCS-BEC cross-over
- Quantum critical point lying beneath the superconducting dome in iron-pnictides
- A Sharp Peak of the Zero-Temperature Penetration Depth at Optimal Composition in BaFe2(As1-xPx)2
- Observation of pseudogap behavior in a strongly interacting Fermi gas
- The BCS-BEC crossover: From ultra-cold Fermi gases to nuclear systems
- Semi-Meissner state and neither type-I nor type-II superconductivity in multicomponent systems
- Strongly paired fermions: Cold atoms and neutron matter
- Pseudogap and spectral function from superconducting fluctuations to the bosonic limit
- Two-component Bose-Einstein Condensates with Large Number of Vortices
- Observation of an orbital interaction-induced Feshbach resonance in 173-Yb
- A strongly interacting gas of two-electron fermions at an orbital Feshbach resonance
- Resonant and crossover phenomena in a multiband superconductor tuning the chemical potential near a band edge
- Shallow pockets and very strong coupling superconductivity in FeSe_xTe_1-x
- Giant superconducting fluctuations in the compensated semimetal FeSe at the BCS-BEC crossover
- The gap amplification at a "shape resonance" in a superlattice of quantum stripes: a mechanism for high Tc
- Evolution of the Normal State of a Strongly Interacting Fermi Gas from a Pseudogap Phase to a Molecular Bose Gas
- Orbital Feshbach Resonance in Alkali-Earth Atoms
- Quantum Materials: Shape Resonances in Superstripes
- Superconductivity in an electron band just above the Fermi level: possible route to BCS-BEC superconductivity
- Electron pairing in the presence of incipient bands in iron-based superconductors
- Transition from BCS pairing to Bose-Einstein condensation in low-density asymmetric nuclear matter
- Superconductivity vs bound state formation in a two-band superconductor with small Fermi energy -- applications to Fe-pnictides/chalcogenides and doped SrTiO3
- Effects of density imbalance on the BCS-BEC crossover in semiconductor electron-hole bilayers
- Quantum vortex core and missing pseudogap in the multi-band BCS-BEC-crossover superconductor FeSe
- Band-edge BCS-BEC crossover in a two-band superconductor: physical properties and detection parameters
- Emergent phenomena in multicomponent superconductivity: an introduction to the focus issue
- Exotic vortex lattices in two-species Bose-Einstein condensates
- High Tc via spin fluctuations from incipient bands: application to monolayers and intercalates of FeSe
- 3D superconducting gap in FeSe from ARPES
- Superfluid Fermi atomic gas as a quantum simulator for the study of neutron-star equation of state
- BEC-BCS Crossover and the Liquid-Gas Phase Transition in Hot and Dense Nuclear Matter
- Strongly correlated Fermi superfluid near an orbital Feshbach resonance: Stability, equation of state and Leggett mode
- BCS-BEC crossover of collective excitations in two-band superfluids
- Two-band superfluidity from the BCS to the BEC limit
- Orbital Feshbach Resonance: A "Wide" Narrow Resonance for Higher Transition Temperature Fermi Superfluid
- Multicomponent electron-hole superfluidity and the BCS-BEC crossover in double bilayer graphene
- Two-band superfluidity and intrinsic Josephson effect in alkaline-earth Fermi gases across an orbital Feshbach resonance
- Excitonic BCS-BEC crossover at finite temperature: Effects of repulsion and electron-hole mass difference
- Three Dimensional Superconductivity in FeSe with Tczero Up to 10.9 K Induced by Internal Strain
- BEC-BCS Crossover in Neutron Matter with Renormalization Group based Effective Interactions
- Superconducting nanofilms: molecule-like pairing induced by quantum confinement
- A strongly interacting Sarma superfluid near orbital Feshbach resonances
- Trapped Yb Fermi gas across an orbital Feshbach resonance
- Coulomb Correlations and Pseudo-gap Effects in a Pre-formed Pair Model for the Cuprates
- Single-particle Excitations and Strong Coupling Effects in the BCS-BEC Crossover Regime of a Rare-Earth Fermi Gas with an Orbital Feshbach Resonance
Cited by in corpus (24)
- Theoretical possibilities for flat-band superconductivity
- A dual-species Bose-Einstein condensate with attractive interspecies interactions
- Fermi-Bose mixtures and BCS-BEC crossover in high-Tc superconductors
- Coexistence of giant Cooper pairs with a bosonic condensate and anomalous behavior of energy gaps in the BCS-BEC crossover of a two-band superfluid Fermi gas
- Dipole dynamics of an interacting bosonic mixture
- BCS-BEC Crossover and Pairing Fluctuations in a Two Band Superfluid/Superconductor: A T Matrix Approach
- Resonant pair-exchange scattering and BCS-BEC crossover in a system composed of dispersive and heavy incipient bands: a Feshbach analogy
- Cooper pairing, flat-band superconductivity and quantum geometry in the pyrochlore-Hubbard model
- Mechanism of screening or enhancing the pseudogap throughout the two-band Bardeen-Cooper-Schrieffer to Bose-Einstein condensate crossover
- Interplay between singlet and triplet pairings in multi-band two-dimensional oxide superconductors
- Potassium-Doped Para-Terphenyl: Structure, Electrical Transport Properties and Possible Signatures of a Superconducting Transition
- Tunable BCS-BEC crossover, reentrant, and hidden quantum phase transitions in two-band superconductors with tunable valence and conduction bands
- Leggett collective excitations in a two-band Fermi superfluid at finite temperatures
- Pairs, trimers and BCS-BEC crossover near a flat band: the sawtooth lattice
- Generalized Crossover in Interacting Fermions within the Low-Energy Expansion
- Berezinskii-Kosterlitz-Thouless phase transition with Rabi-coupled bosons
- Pseudogap and Strong Pairing Induced by Incipient and Shallow Bands in the Quasi-Two-Dimensional KCaFeAsF
- Emergent Fano-Feshbach resonance in two-band superconductors with an incipient quasi-flat band: Enhanced critical temperature evading particle-hole fluctuations
- Shift of the critical temperature in superconductors: a self-consistent approach
- BCS-BCS crossover between atomic and molecular superfluids in a Bose-Fermi mixture
- Hybrid-pair superfluidity in a strongly driven Fermi gas
- Hidden Pseudogap and Excitation Spectra in a Strongly Coupled Two-Band Superfluid/Superconductor
- Superfluid properties of an ultracold Fermi gas with an orbital Feshbach resonance in the BCS-BEC crossover region
- Two-band atomic superfluidity in the presence of an orbital Feshbach resonance