A strong-coupling mean-field theory for the spin-liquid paramagnetic non-superconducting phase of high-Tc cuprates

Full text: A strong-coupling mean-field theory for the spin-liquid paramagnetic non-superconducting phase of the p- and n-type High-Tc cuprates is developed. This theory was applied to the effective t-t,-t,,-J* model with the ab-initio calculated parameters and with the three-site correlated hopping. The static spin-spin and kinematic correlation functions beyond Hubbard-I approximation are calculated self-consistently. The evolution of the Fermi surface and band dispersion is obtained for the wide range of doping concentrations x. For p-type systems the three different types of behavior are found and the transitions between these types are accompanied by the changes in the Fermi surface topology. Thus a quantum phase transitions take place at x=0.15 and at x=0.23. Due to the different Fermi surface topology for n-type cuprates we have found only one quantum critical concentration, x=0.2. The calculated doping dependence of the nodal Fermi velocity and the effective mass are in good agreement with the recent experimental data. (authors)