The Josephson effect throughout the BCS-BEC crossover

Abstract

We study the stationary Josephson effect for neutral fermions across the BCS-BEC crossover, by solving numerically the Bogoliubov-de Gennes equations at zero temperature. The Josephson current is found to be considerably enhanced for all barriers at about unitarity. For vanishing barrier, the Josephson critical current approaches the Landau limiting value which, depending on the coupling, is determined by either pair-breaking or sound-mode excitations. In the coupling range from the BCS limit to unitarity, a procedure is proposed to extract the pairing gap from the Landau limiting current.

4 pages, 3 figures; improved version to appear in Phys. Rev. Lett

References in corpus (5)

• Vortices and Superfluidity in a Strongly Interacting Fermi Gas
• Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
• Weakly bound dimers of fermionic atoms
• BCS-BEC crossover at finite temperature in the broken-symmetry phase
• Time-dependent Gross-Pitaevskii equation for composite bosons as the strong-coupling limit of the fermionic BCS-RPA approximation

Cited by in corpus (13)

• Theory of ultracold Fermi gases
• Critical velocity for superfluid flow across the BEC-BCS crossover
• DC Josephson Effect with Fermi gases in the Bose-Einstein regime
• Macroscopic Periodic Tunneling of Fermi Atoms in the BCS-BEC Crossover
• Critical velocity of superfluid flow through single barrier and periodic potentials
• Josephson plasma oscillations and the Gross-Pitaevskii equation: Bogoliubov approach vs two-mode model
• BCS-BEC crossover in a random external potential
• Equation of state and effective mass of the unitary Fermi gas in a 1D periodic potential
• DC and AC Josephson effects with superfluid Fermi atoms across a Feshbach resonance
• Effects of periodic potentials on the critical velocity of superfluid Fermi gases in the BCS-BEC crossover
• Effect of Disorder in BCS-BEC Crossover
• Spin-asymmetric Josephson plasma oscillations
• Collective excitation and stability of flow-induced gapless Fermi superfluids