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. Paying attention to the effect of the transfer energy $t_{pp}$ between the nearest neighbor oxygen-sites, we calculate the critical exponent of correlation functions $K_ρ$ based on the Luttinger liquid relations and the ground state energy $E_0(ϕ)$ 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 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.

4 pages, RevTex + 5 PS figures included