Comprehensive study of high-Tc interface superconductivity

Using ALL-MBE technique, we have synthesized different heterostructures consisting of an insulator La2CuO4 (I) and a metal La1.56Sr0.44CuO4 (M) layer neither of which is superconducting by itself. The M–I bilayers were superconducting with a critical temperature Tc≈30–36 K. This highly robust phenomenon is confined within 1–2 nm from the interface and is primarily caused by the redistribution of doped holes across the interface. In this paper, we present a comprehensive study of the interface superconductivity by a range of experimental techniques including transport measurements of superconducting properties.