Hole filling and interlayer coupling in YBa2 Cu3 07/PrBa2 Cu307 superlattices

Charge transfer effects in YBa2Cu3O7/PrBa2Cu3O7 superlattices have been proposed by many authors as the origin of the experimentally observed strong depression of the critical temperature. We performed self-consistent LMTO-ASA calculations and found that no remarkable change in the electronic structure of the superconducting CuO2 planes occurs in the studied structures, when the PBCO layer thickness is varied. The observed depression of the critical temperature does not seem to be originated intrinsically by a severe modification of the electronic structure or by the hole-filling mechanism.