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 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.
A. A. Aligia, A. Anfossi, L. Arrachea, C. Degli Esposti Boschi, A. O. Dobry, C. Gaaza, et al. (2007). Incommensurability and unconventional superconductor to insulator transition in the Hubbard model with bond-charge interaction. PHYSICAL REVIEW LETTERS, 99, 206401-1-206401-4.
Incommensurability and unconventional superconductor to insulator transition in the Hubbard model with bond-charge interaction.
DEGLI ESPOSTI BOSCHI, CRISTIAN;ORTOLANI, FABIO;
2007
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 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
