Pairing, charge, and spin correlations in the three-band Hubbard model - art. no. 115112

Using the constrained path Monte Carlo method, we simulated the two-dimensi onal; three-band Hubbard model to study pairing, charge, and spin correlati ons as a function of electron and hole doping and the Coulomb repulsion V-p d between charges on neighboring Cu and O lattice sites. As a function of d istance, both the d(x2-y2)-wave and extended s-wave pairing correlations de cayed quickly. In the charge-transfer regime, increasing V-pd decreased the long-range part of the correlation functions in both channels, while in th e mixed-valent regime, it increased the long-range part of the s-wave behav ior but decreased that of the d-wave behavior. Still the d-wave behavior do minated. At a given doping, increasing V-pd increased the spin-spin correla tions in the charge-transfer regime but decreased them in the mixed-valent regime. Also, increasing Vpd suppressed the charge-charge correlations betw een neighboring Cu and O sites. Electron and hole doping away from half-fil ling was accompanied by a rapid suppression of antiferromagnetic correlatio ns. Our results suggest that adding a repulsive V-pd to the model does not enhance its tendency toward superconductivity even though the behavior of t he spin structure factor is consistent with the properties of some high-tem perature superconducting materials.