Renormalized band structure of CuO2 layers in superconducting compounds: A mean-field approach.

Abstract

We have analyzed the band structure of a ${\mathrm{CuO}}_{2}$ plane including two copper orbitals (${\mathit{d}}_{\mathit{x}}^{2}$-${\mathit{y}}^{2}$ and ${\mathit{d}}_{3\mathit{z}}^{2}$-${\mathit{r}}^{2}$) and two oxygen orbitals (${\mathit{p}}_{\mathit{x}}$,${\mathit{p}}_{\mathit{y}}$) in a tight-binding approximation. A Hubbard interaction between copper d holes has been considered with use of a slave-boson technique, while oxygen and copper holes interact via a nearest-neighbors Coulombic repulsion treated in the Hartree-Fock approximation. The resulting band structure opens the way to a comparison with the experiments and to some theoretical implications on the pairing mechanism of high-${\mathit{T}}_{\mathit{c}}$ superconductors.