Superconducting thin film having columnar pin retaining center using nano-dots

Abstract

A superconducting thin film is disclosed having columnar pinning centers utilizing nano dots, and comprising nano dots () which are formed insularly on a substrate () and three-dimensionally in shape and composed of a material other than a superconducting material and also other than a material of which the substrate is formed, columnar defects () composed of the superconducting material and grown on the nano dots (), respectively, a lattice defect () formed on a said columnar defect (), and a thin film of the superconducting material () formed in those areas on the substrate which are other than those where said columnar defects are formed. The superconducting thin film is prepared by depositing the material other than the superconducting material on the substrate () while controlling the substrate temperature, the rate of deposition of the material and the film thickness of the material deposited so to coagulate the deposited material to form the nano dots (), and then growing a thin film of the superconducting material () on the substrate (). An improved superconducting this film is thus provided which regardless of its type is at least ten times higher in critical current density than an exiting superconducting thin film, and which can also be manufactured at a low cost. And, being large in critical superconducting current density and critical superconducting magnetic field, it is advantageously applicable to the technical fields of cryogenic electronics and microwaves.