Triplet superconductivity in quasionedimensional systems
Abstract
We study a Hubbard Hamiltonian, including a quite general nearestneighbor interaction, parametrized by repulsion V, exchange interactions J_{z},J_{⊥}, bondcharge interaction X, and hopping of pairs W. The case of correlated hopping, in which the hopping between nearest neighbors depends upon the occupation of the two sites involved, is also described by the model for sufficiently weak interactions. We study the model in one dimension with usual continuumlimit field theory techniques, and determine the phase diagram. For arbitrary filling, we find a very simple necessary condition for the existence of dominant triplet superconducting correlations at large distance in the spin SU(2) symmetric case: 4V+J<0. In the correlatedhopping model, the threebody interaction should be negative for positive V. We also compare the predictions of this weakcoupling treatment with numerical exact results for the correlatedhopping model obtained by diagonalizing small chains and using a Berry phase to determine the opening of the spin gap.
 Publication:

Physical Review B
 Pub Date:
 December 1999
 DOI:
 10.1103/PhysRevB.60.15332
 arXiv:
 arXiv:condmat/9907491
 Bibcode:
 1999PhRvB..6015332A
 Keywords:

 74.20.Mn;
 74.25.Dw;
 71.10.Fd;
 Nonconventional mechanisms;
 Superconductivity phase diagrams;
 Lattice fermion models;
 Condensed Matter  Superconductivity
 EPrint:
 8 pages, 3 figures