Incommmensurability and Unconventional Superconductor to Insulator Transition in the Hubbard Model with Bond-Charge Interaction

A. A. Aligia; A. Anfossi; L. Arrachea; C. Degli Esposti Boschi; A. O. Dobry; C. Gazza; A. Montorsi; F. Ortolani; M. E. Torio

doi:10.1103/PhysRevLett.99.206401

Incommmensurability and Unconventional Superconductor to Insulator Transition in the Hubbard Model with Bond-Charge Interaction

A. A. Aligia, A. Anfossi, L. Arrachea, C. Degli Esposti Boschi, A. O. Dobry, C. Gazza, A. Montorsi, F. Ortolani, M. E. Torio

DOI 10.1103/PhysRevLett.99.206401 · Physical Review Letters

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

We determine the quantum phase diagram of the one-dimensional Hubbard model with bond-charge interaction X in addition to the usual Coulomb repulsion U>0 at half-filling. For large enough X<t the model shows three phases. For large U the system is in the spin-density wave phase as in the usual Hubbard model. As U decreases, there is first a spin transition to a spontaneously dimerized bond-ordered 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.