OXIDE SUPERCONDUCTOR JOSEPHSON JUNCTION ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide an oxide superconductor Josephson junction element structure reducing a stress to a superconductor thin film due to lattice mismatching generating in an interface of a superconductor thin film/tunnel barrier insulator layer/superconductor thin film and further alleviating deterioration of superconducting characteristics by using a lattice matching tunnel barrier insulator layer. SOLUTION: An oxide superconductor thin film containing a composition represented by a first LnBa2 Cu3 Ox 2 (Ln: at least one type of elements of Y and lanthanide element) in which an a-axis is oriented to a board main surface and a c-axis is oriented in a film surface, an insulator thin film containing a composition represented by an Ln'2 Cu3 O4 3 (Ln': lanthanide element), and an oxide superconductor thin film containing a composition represented by a second LnBa2 Cu3 Ox 4 in which an a-axis is oriented to a substrate main surface and a c-axis is oriented in a film surface are sequentially stacked from a substrate side to form the oxide superconductor Josephson junction element.