ar X iv : c on d - m at / 9 40 70 48 v 1 1 0 Ju l 1 99 4 Phase diagrams of electronic state on One Dimensional d - p

We investigate the one-dimensional(1D) d-p model, simulating a Cu-O linear chain with strong Coulomb repulsion, by using the numerical diagonalization method. Using the Luttinger liquid theory, we obtained phase diagrams of the ground state on U d − U pd plane, where U d and U pd represent on-site interaction at d-sites and the nearest-neighbor interaction between p-and d-sites respectively. In the weak coupling region, they agree with the g-ology; a su-perconducting phase (SC(I)) is restricted to attractive interaction U pd < 0. On the other hand, in the strong coupling region, we found a novel supercon-ducting phase(SC(II)) for repulsive interaction U pd > |U d | and a insulating state with a charge gap for U d > U c d and U pd > U c pd with critical values U c d and U c pd at half-filling. Away from half-filling, another superconducting phase suggests that the SC(I) and SC(II) include the Luther-Emery region (with spin-gap) in part, while the SC(III) belongs to Tomonaga-Luttinger region (without spin-gap) in whole.