Modified Fermi-sphere, pairing gap and critical temperature for the BCS-BEC crossover
arXiv:0912.4050 · doi:10.1103/PhysRevA.81.063619
Abstract
We investigate the phase diagram of two-component fermions in the BCS-BEC crossover. Using functional renormalization group equations we calculate the effect of quantum fluctuations on the fermionic self-energy parametrized by a wavefunction renormalization, an effective Fermi radius and the gap. This allows us to follow the modifications of the Fermi surface and the dispersion relation for fermionic excitations throughout the whole crossover region. We also determine the critical temperature of the second order phase transition to superfluidity. Our results are in agreement with BCS theory including Gorkov's correction for small negative scattering length a and with an interacting Bose gas for small positive a. At the unitarity point the result for the gap at zero temperature agrees well with Quantum-Monte-Carlo simulations while the critical temperature differs.
arXiv comment8 pages, 7 figures, minor change in figures 2 and 3 (correction of axis label)
References in corpus (51)
- Exact evolution equation for the effective potential
- Observation of resonance condensation of fermionic atom pairs
- Non-Perturbative Renormalization Flow in Quantum Field Theory and Statistical Physics
- Condensation of Pairs of Fermionic Atoms Near a Feshbach Resonance
- Aspects of the Functional Renormalisation Group
- Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
- Optimised Renormalisation Group Flows
- Weakly bound dimers of fermionic atoms
- Superfluid Fermi Gases with Large Scattering Length
- Optimisation of the exact renormalisation group
- Equation of state of a Fermi gas in the BEC-BCS crossover: a quantum Monte Carlo study
- Molecular Probe of Pairing in the BEC-BCS Crossover
- Thermodynamics of the BCS-BEC crossover
- Superfluidity of spin-polarized 6Li
- Spin 1/2 Fermions in the Unitary Regime: A Superfluid of a New Type
- Critical Temperature and Thermodynamics of Attractive Fermions at Unitarity
- The transition temperature of the dilute interacting Bose gas
- Renormalization Flow of Bound States
- Quantum Monte Carlo Studies of Superfluid Fermi Gases
- Quantum Fluctuations in the Superfluid State of the BCS-BEC Crossover
- Transition temperature of a dilute homogeneous imperfect Bose gas
- BCS-BEC crossover at finite temperature for superfluid trapped Fermi atoms
- On the correct strong-coupling limit in the evolution from BCS superconductivity to Bose-Einstein condensation
- Epsilon expansion for a Fermi gas at infinite scattering length
- Spectral Functions and rf Response of Ultracold Fermionic Atoms
- Renormalization group fixed points, universal phase diagram, and 1/N expansion for quantum liquids with interactions near the unitarity limit
- Quantum Monte Carlo Simulations of the BCS-BEC Crossover at Finite Temperature
- Mind The Gap
- BCS-BEC crossover at finite temperature in the broken-symmetry phase
- Quantitative comparison between theoretical predictions and experimental results for the BCS-BEC crossover
- Exact flow equation for composite operators
- Critical Temperature Curve in the BEC-BCS Crossover
- Fermi gas near unitarity around four and two spatial dimensions
- Flow Equations for the BCS-BEC Crossover
- Renormalization Group Theory for the Imbalanced Fermi Gas
- Particle-hole fluctuations in the BCS-BEC Crossover
- Pairing in Many-Fermion Systems: An Exact Renormalisation Group Treatment
- Pairing and Superfluid Properties of Dilute Fermion Gases at Unitarity
- Functional renormalization for Bose-Einstein Condensation
- Universality in Phase Transitions for Ultracold Fermionic Atoms
- Renormalisation Flow and Universality for Ultracold Fermionic Atoms
- Renormalization group flow for fermionic superfluids at zero temperature
- Next-to-next-to-leading-order epsilon expansion for a Fermi gas at infinite scattering length
- Efimov effect from functional renormalization
- Unusual thermodynamical and transport signatures of short coherence length superconductors: A BCS Bose-Einstein crossover approach
- Three-body scattering from nonperturbative flow equations
- Unitary Fermi gas at finite temperature in the epsilon expansion
- Functional Integral for Ultracold Fermionic Atoms
- BEC-BCS Crossover in the Epsilon Expansion
- Nonperturbative thermodynamics of an interacting Bose gas
- Strongly interacting Fermi systems in 1/N expansion: From cold atoms to color superconductivity
Cited by in corpus (30)
- The nonperturbative functional renormalization group and its applications
- Fermion Interactions and Universal Behavior in Strongly Interacting Theories
- The BCS-BEC crossover: From ultra-cold Fermi gases to nuclear systems
- Critical behavior of the (2+1)-dimensional Thirring model
- Ultracold atoms and the Functional Renormalization Group
- Critical (Chiral) Heisenberg Model with the Functional Renormalisation Group
- Phase structure of spin-imbalanced unitary Fermi gases
- Gap equation with pairing correlations beyond mean field and its equivalence to a Hugenholtz-Pines condition for fermion pairs
- Critical temperature and superfluid gap of the Unitary Fermi Gas from Functional Renormalization
- Renormalization group study of Bose polarons
- Low-temperature thermodynamics of the unitary Fermi gas: superfluid fraction, first sound and second sound
- Renormalization theory for the Fulde-Ferrell-Larkin-Ovchinnikov states at
- Sarma phase in relativistic and non-relativistic systems
- Convergence of a renormalization group approach to dimer-dimer scattering
- Finite-size and Particle-number Effects in an Ultracold Fermi Gas at Unitarity
- Fermionic Functional Renormalization Group Approach to Superfluid Phase Transition
- Efimov physics from the functional renormalization group
- Error estimates and specification parameters for functional renormalization
- Effective potential and quantum criticality for imbalanced Fermi mixtures
- Zero density limit extrapolation of the superfluid transition temperature in a unitary atomic Fermi gas on a lattice
- Dimensional crossover in ultracold Fermi gases from Functional Renormalisation
- Detecting the phase transition in a strongly-interacting Fermi gas by unsupervised machine learning
- Spectral properties and observables in ultracold Fermi gases
- Functional renormalization for the BCS-BEC crossover
- Fermionic Functional Renormalization Group Approach to Bose-Einstein Condensation of Dimers
- Functional renormalisation group approach to the finite-temperature Bose polaron
- Functional renormalization group approach to conventional theory of superfluidity and beyond
- Functional-renormalization-group approach to strongly coupled Bose-Fermi mixtures in two dimensions
- Functional Renormalization Analytically Continued
- Multi-Regulator Functional Renormalization Group for Many-Fermion Systems