Finiteness of the Hopping Induced Energy Corrections in Cuprates

TL;DR

This paper investigates the energy corrections in cuprates within a two-band Hubbard model, demonstrating that finite energy spectra are achievable at all doping levels through a specific renormalization of the hopping term.

Contribution

It extends previous mean field Green function solutions by showing how to obtain finite energy spectra across all doping levels via a renormalized hopping term.

Findings

Finite energy spectra are obtained at all doping levels.

Divergence occurs in the energy spectrum as doping approaches zero.

Renormalization of the hopping term is essential for finite spectra.

Abstract

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.