The role of the charge density fluctuations and many-body Coulomb correlations in the mechanism of high-temperature superconductivity in cuprate metal-oxides

The charge-fluctuation (plasmon) mechanism of the d-wave Cooper pairing in high-Tc superconductors (HTS) is considered. The mechanism is due to the interaction between the charge carriers and the collective low-frequency excitations of the electron density. Sense the one-particle spectrum of layered cuprate metal-oxide crystals contains extended anisotropic saddle-point singularities ('flat zones') with anomalously high density of states, the collective electron spectrum can develop attenuating long-wavelength charge density fluctuations which suppress the screened static Coulomb repulsion in the region of small transferred momenta. As a result, the effective inter electron attraction appears in the d-wave Cooper channel, which is enhanced significantly by the many-body Coulomb correlations of the local field type described by the Coulomb vertices. The attraction induces the Cooper pairing with the symmetry dx2-y2 of the superconducting order parameter and is capable of ensuring quite high maximal critical temperatures, Tc approx 100 K, with optimal doping of cuprate metal-oxides compounds.The allowance for the anisotropy of the electron-phonon interaction enables us to describe a weak isotopic oxygen effect in HTS compounds