Relative Phase and Josephson Dynamics between Weakly Coupled Richardson Models
arXiv:1303.3544 · doi:10.1103/PhysRevB.87.174506
Abstract
We consider two weakly coupled Richardson models to study the formation of a relative phase and the Josephson dynamics between two mesoscopic attractively interacting fermionic systems: our results apply to superconducting properties of coupled ultrasmall metallic grains and to Cooper-pairing superfluidity in neutral systems with a finite number of fermions. We discuss how a definite relative phase between the two systems emerges and how it can be conveniently extracted from the many-body wavefunction: we find that a definite relative phase difference emerges even for very small numbers of pairs ~10. The Josephson dynamics and the current-phase characteristics are then investigated, showing that the critical current has a maximum at the BCS-BEC crossover. For the considered initial conditions a two-state model gives a good description of the dynamics and of the current-phase characteristics.
20 pages, 15 figures
References in corpus (11)
- Theory of ultracold Fermi gases
- Gaudin models solver based on the Bethe ansatz/ordinary differential equations correspondence
- The Josephson effect throughout the BCS-BEC 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
- Equation of state and effective mass of the unitary Fermi gas in a 1D periodic potential
- Dynamical correlation functions of the mesoscopic pairing model
- Bethe Ansatz approach to the pairing fluctuations in the mesoscopic regime
- Effects of periodic potentials on the critical velocity of superfluid Fermi gases in the BCS-BEC crossover
- Anisotropic Ginzburg-Landau and Lawrence-Doniach Models for Layered Ultracold Fermi Gases