Ai. Liechtenstein et al., QUASI-PARTICLE BANDS AND SUPERCONDUCTIVITY IN BILAYER CUPRATES, Physical review. B, Condensed matter, 54(17), 1996, pp. 12505-12508
We analyze the generic features of the energy spectrum for two coupled
CuO2 layers with a realistic extended Hubbard model. The quasiparticl
e bands exhibit flat regions near X(Y) points in the Brillouin zone wi
th a large reduction of the bonding-antibonding splitting and pinning
of extended van Hove singularity to the Fermi level, which is more eff
icient for bilayers than for a single layer. In contrast to the result
s with simpler models, the superconducting temperature for d(x2-y2) pa
iring is not lowered by the bilayer hopping.