PROJECTION OPERATOR MEAN-FIELD SOLUTION OF THE 2-DIMENSIONAL HUBBARD-MODEL

A projection operator mean field (POME) calculation of the two-dimensi onal three-band Hubbard model of the CuO2 lattice is presented in this work, which consists of two parts. In the first part the method and c omputational techniques are outlined. We will show that the POME metho d can be easily generalized all the way to many atoms per unit cell wi th s, p, d orbitals included, and requires very small computer effort. An application to study the effect on the solution of each parameter will follow in the second part. Our results show that increasing Coulo mb repulsions U-d, U-p, U-dp, and change-transfer energy Delta enhance s the antiferromagnetism, and increasing hopping parameters t(dp) and t(p) supresses the antiferromagnetism. The binding energy of the satel lite is enhanced by increasing the values of U-d, t(dp), and t(p), and supressed by increasing the values of U-dp, U-p, and Delta.