QUASI-PARTICLE BANDS AND SUPERCONDUCTIVITY IN BILAYER CUPRATES

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.