Theory for superconducting properties of the cuprates: Doping dependence of the electronic excitations and shadow states

The superconducting phase of the 2D one-band Hubbard model is studied within the FLEX approximation and by using an Eliashberg theory. We investigate the doping dependence of T-c, of the gap function Delta(k,omega) and of tire effective pairing interaction. Thus we find that T-c becomes maximal for 13% doping. In overdoped systems T-c decreases due to the weakening of the antiferromagnetic correlations, while in the underdoped systems due to the decreasing quasi-particle lifetimes. Furthermore, we find shadow states below T-c which affect the electronic excitation spectrum and lead to fine structure in photoemission experiments.