HOLE FILLING AND INTERLAYER COUPLING IN YBA2CU3O7 PRB2CU3O7 SUPERLATTICES/

Charge transfer effects in YBa2Cu3O7/PrBa2Cu3O7 superlattices have bee n proposed by many authors as the origin of the experimentally observe d strong depression of the critical temperature. We performed self-con sistent LMTO-ASA calculations and found that no remarkable change in t he electronic structure of the superconducting CuO2 planes occurs in t he studied structures, when the PBCO layer thickness is varied. The ob served depression of the critical temperature does not seem to be orig inated intrinsically by a severe modification of the electronic struct ure or by the hole-filling mechanism.