Finiteness of the Hopping Induced Energy Corrections in Cuprates

The paper continues the rigorous investigations of the mean field Green function solution of the effective two-dimensional two-band Hubbard model [N. M. Plakida et al., Phys. Rev. B, Vol.51, 16599 (1995)] of the superconducting phase transitions in cuprates, started in [Gh. Adam, S. Adam, J. Phys. A: Math. Theor., Vol.40, 11205 (2007)]. Discussion of the $(\delta, T)$ phase diagram of the model points to the divergence of the energy spectrum in the limit of vanishing doping $\delta$. Finite energy spectra at all possible doping rates $\delta$ are obtained provided the hopping part of the effective Hamiltonian is renormalized with an effective factor pointing to the site-pairs availability for fermion hopping processes.