Superconductivity in ultrathin artificial cuprate structures

Abstract

Layer-by-layer pulsed-laser deposition has been used to grow ultrathin superconducting (Ba0.9Nd0.1)CuO2+x/CaCuO2 artificial structures with various thicknesses of the two constituent layers. Superconductivity was observed in the ultrathin structure consisting of a single CaCuO2 superconducting block sandwiched between two (Ba0.9Nd0.1)CuO2+x blocks. The results obtained allowed an experimental demonstration of the currently accepted structural model for high TC superconductivity, which requires the presence in the same structure of two blocks with different functional properties: the superconducting infinite layer block and the nonsuperconducting charge reservoir block.