Incommmensurability and Unconventional Superconductor to Insulator Transition in the Hubbard Model with BondCharge Interaction
Abstract
We determine the quantum phase diagram of the onedimensional Hubbard model with bondcharge interaction X in addition to the usual Coulomb repulsion U>0 at halffilling. For large enough X<t the model shows three phases. For large U the system is in the spindensity wave phase as in the usual Hubbard model. As U decreases, there is first a spin transition to a spontaneously dimerized bondordered wave phase and then a charge transition to a novel phase in which the dominant correlations at large distances correspond to an incommensurate singlet superconductor.
 Publication:

Physical Review Letters
 Pub Date:
 November 2007
 DOI:
 10.1103/PhysRevLett.99.206401
 arXiv:
 arXiv:0704.0717
 Bibcode:
 2007PhRvL..99t6401A
 Keywords:

 71.10.Fd;
 71.10.Hf;
 71.10.Pm;
 71.30.+h;
 Lattice fermion models;
 NonFermiliquid ground states electron phase diagrams and phase transitions in model systems;
 Fermions in reduced dimensions;
 Metalinsulator transitions and other electronic transitions;
 Condensed Matter  Strongly Correlated Electrons;
 Condensed Matter  Superconductivity
 EPrint:
 5 pages, 3 figures