Mesoscopic BCS pairing in the repulsive 1d-Hubbard model
arXiv:cond-mat/0509554 · doi:10.1103/PhysRevB.73.214513
Abstract
We study mesoscopic pairing in the one dimensional repulsive Hubbard model and its interplay with the BCS model in the canonical ensemble. The key tool is comparing the Bethe ansatz equations of the two models in the limit of small Coulomb repulsion. For the ordinary Hubbard interaction the BCS Bethe equations with infinite pairing coupling are recovered; a finite pairing is obtained by considering a further density-dependent phase-correlation in the hopping amplitude of the Hubbard model. We find that spin degrees of freedom in the Hubbard ground state are arranged in a state of the BCS type, where the Cooper-pairs form an un-condensed liquid on a ``lattice'' of single particle energies provided by the Hubbard charge degrees of freedom; the condensation in the BCS ground state corresponds to Hubbard excitations constituted by a sea of spin singlets.
15 pages, 6 figures. To be published on Physical Review B
References in corpus (18)
- Spectroscopy of discrete energy levels in ultrasmall metallic grains
- Exactly solvable Richardson-Gaudin models for many-body quantum systems
- Strongly Correlated Superconductivity
- Integrability of the pairing hamiltonian
- A small superconducting grain in the canonical ensemble
- Integrble Models in Condensed Matter Physics
- Generating function of correlators in the sl_2 Gaudin model
- Exact correlation functions of the BCS model in the canonical ensemble
- A new class of exactly solvable interacting fermion models in one dimension
- Electronic Mechanism of Superconductivity in the Cuprates, C, and Polyacenes
- Evaluation of the BCS Approximation for the Attractive Hubbard Model in One Dimension
- The BCS model and the off shell Bethe ansatz for vertex models
- Ground state of one-dimensional bosons with delta interaction: link to the BCS model
- Electrostatic analogy for integrable pairing force Hamiltonians
- Exact solution of generalized Schulz-Shastry type models
- Quasi-classical descendants of disordered vertex models with boundaries
- Even-Odd and Super-Even Effects in the Attractive Hubbard Model
- BCS and Attractive Hubbard Model Comparative Study