Analysis of the BCS equations for anisotropic superconductivity Original Research Article

Anisotropic superconducting states have been studied within a generalized Hubbard model and the BCS formalism, which leads to two coupled integral equations that determine the chemical potential and the superconducting gap. In this work, these equations are analyzed. Their integrand functions have sharp walls at the Fermi surface, which mainly determine the integrals. Furthermore, the chemical potential obtained from these equations is close to that from the mean-field density of states (DOS) and quite different to that from non-interacting DOS. Finally, the calculated condensation energy as a function of doping is compared with experimental data obtained from La2−xSrxCuO4 and Y0.8Ca0.2Ba2Cu3O7−δ.