A superconducting thin film is disclosed having columnar pinning centers
utilizing nano dots, and comprising nano dots (3) which are formed
insularly on a substrate (2) 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
(4) composed of the superconducting material and grown on the nano dots
(3), respectively, a lattice defect (6) formed on a said columnar defect
(4), and a thin film of the superconducting material (5) 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 (2) 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
(3), and then growing a thin film of the superconducting material (5) on
the substrate (2). 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.