  We consider an extended Hubbard model with nearest-neighbor correlated
hopping and next nearest-neighbor hopping t' obtained as an effective model for
cuprate superconductors. Using a generalized Hartree-Fock BCS approximation, we
find that for high enough t' and doping, antiferromagnetism is destroyed and
the system exhibits d-wave superconductivity. Near optimal doping we consider
the effect of antiferromagnetic spin fluctuations on the normal self-energy
using a phenomenological susceptibility. The resulting superconducting critical
temperature as a function of doping is in good agreement with experiment.

Superconductivity