Kosterlitz-Thouless transition and charge redistribution in the superconductivity of YBCO/PBCO superlattices

Recent experimental measurements of the resistive transition in YBa₂{Cu}₃O_7-x/PrBa₂{Cu}₃O_7-x superlattices show a dramatic suppression in the resistive transition temperature Tc as the thickness of the Pr layer increases while the thickness of the Y layer decreases. We show that the qualitative features of these experiments (and in particular most of the suppression in Tc) can be accounted for within the Kosterlitz-Thouless theory. A small further suppression in Tc is shown to occur due to charge transfer from Y to the Pr layers.