A NEARLY ANTIFERROMAGNETIC FERMI-LIQUID APPROACH TO HIGH-T(C)

I present the results of extensive numerical calculations of a system of coupled quasiparticles and spin fluctuations using the Eliashberg formalism for YBa2Cu3O7. Following a brief review of the phenomenological model and the computational approach, the sensitivity of T(c) to the hole concentration and to the details of the spin fluctuation spectrum is examined. The results of the influence of potential impurity scattering are discussed. It is shown, with the aid of a simple model to describe the disruption of the local magnetic brought about by the substitution of Zn, that the latter has a strong influence on T(c). The competition between antiferromagnetic and superconducting instabilities is considered and it is found that, for the model parameters used, the instability to a superconducting state always comes first.