EFFECT OF CORRELATED-HOPPING INTERACTION ON A ONE-DIMENSIONAL EXTENDED HUBBARD MODEL WITH SPIN-EXCHANGE INTERACTION

By using the field-theoretical techniques combining bosonization with renormalization group, we study a one-dimensional (1D) model of interacting electrons with on-site repulsion (U > 0), nearest-neighbor (nn) exchange (J) and correlated-hopping (t(2), t(3)) interactions at weak coupling. In the case of a half-filled band, the two-body interaction t(2) does not influence phase diagram of the model, while the presence of three-body interaction t(3) makes the physics of the system highly non-trivial. By a Hartree-Fock decoupling, the effects of t(3) bring about hopping of pairs, V -like (nn Coulomb interaction) and isotropic exchange terms in the reduced model Hamiltonian. Interestingly, a negative t(3) provides a possibility for the occurrence of the triplet superconductivity in 1D system with purely repulsive interactions (U, J > 0). The ground state phase diagram including the insulating and superconducting phases is discussed analytically.