arXiv:cond-mat/9809187 · Physical review. B, Condensed matter
dx2−y2 superconductivity in a generalized Hubbard model
Liliana Arrachea, Armando A. Aligia
Abstract
We consider an extended Hubbard model with nearest-neighbor correlated hopping and next-nearest-neighbor hopping ${t}^{\ensuremath{'}}$ obtained as an effective model for cuprate superconductors. Using a generalized Hartree-Fock BCS approximation, we find that for high enough ${t}^{\ensuremath{'}}$ 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.