Superconductivity of the One-Dimensional d-p Model with p-p Transfer

Abstract

Using the numerical diagonalization method, we investigate the one-dimensional d-p model, simulating a Cu-O linear chain with strong Coulomb repulsions. Considering the effect of the transfer energy t_pp between the nearest neighbor oxygen-sites, we calculate the critical exponent of the correlation functions K_ρ based on the Luttinger liquid relations and the ground state energy E₀(φ) as a function of an external flux φ.We find that the transfer t_pp increases the charge susceptibility and the exponent K_ρ in cooperation with the repulsion U_d at the Cu site. We also show that anomalous flux quantization occurs for K_ρ>1.The superconducting region is presented on a phase diagram of U_d vs. t_pp plane.