Vi. Belinicher et Al. Chernyshev, CONSISTENT LOW-ENERGY REDUCTION OF THE 3-BAND MODEL FOR COPPER OXIDESWITH O-O HOPPING TO THE EFFECTIVE T-J MODEL, Physical review. B, Condensed matter, 49(14), 1994, pp. 9746-9756
A full three-band model for the CuO2 plane with inclusion of all essen
tial interactions-Cu-O and O-O hopping, repulsion at the copper and ox
ygen and between them-is considered. A general procedure of the low-en
ergy reduction of the primary Hamiltonian to the Hamiltonian of the ge
neralized t-t'-J model is developed. An important role of the direct O
-O hopping is discussed. Parameters of the effective low-energy model
(the hopping integral, the band position, and the superexchange consta
nt J) are calculated. An analysis of the obtained data shows that the
experimental value of J fixes the charge-transfer energy DELTA = (epsi
lon(p) - epsilon(d)) in a narrow region of energies.