Relaxation of the electronic states at a thin-layer YBa 2Cu 3O 7/PrBa 2Cu 3O 7 interface

We discuss in detail spin-polarized electronic structure calculations for the 1 × 1 YBa ₂Cu ₃O ₇/PrBa ₂Cu ₃O ₇ superlattice. Our results are based on the full-potential linear augmented plane wave method and the generalized gradient approximation for the exchange-correlation functional. The on-site Coulomb interaction affecting the correlated Cu 3d and Pr 4f electrons is taken into consideration. At first glance the YBa ₂Cu ₃O ₇/PrBa ₂Cu ₃O ₇ interface appears to be inert, i.e., the electronic states do not show a clear sign of interaction between the two component materials. Nonetheless, a total energy analysis points to a significant modification of the magnetic coupling in the vicinity of the interface due to the relaxation of the electronic structure.