Superconductivity in artificial cuprate structures grown by laser molecular beam epitaxy

Pulsed laser deposition in a molecular beam epitaxy environment has been used to deposit high quality thin films of BaCuO2+x, CaCuO2, and superconducting (BaCuO2+x)(2)/(CaCuO2)(2) artificial superlattices. In situ reflection high energy electron diffraction (RHEED) has shown that the situ x-ray diffraction spectra growth mechanism is two dimensional, and ex confirmed the growth rate deduced from RHEED oscillations. The BaCuO2+xCaCuO2 films alone are not superconducting; however, in infinite layer based heterostructures the occurrence of charge transfer amongst layers containing different alkaline earth ions can give rise to superconductivity. Structural features of these heterostructures can be engineered over a wide range and, consequently, their superconducting properties studied.