According to the structure for reducing the area of the
SQUID superconducting loop and the preparation method thereof provided by the invention, the laminated structure is formed on the
silicon substrate, and then the laminated structure is accurately etched, so that the 3D nano bridge junction is formed on the slope surface of the laminated structure and stretches across the insulating layer, and therefore, batch preparation of the structure for reducing the area of the
SQUID superconducting loop can be realized; according to the
SQUID probe, large-scale application of the SQUID probe is more facilitated, the plane of the 3D nanometer bridge junction is perpendicular to the plane where the SQUID
superconducting loop is located, so that the width of the 3D nanometer bridge junction does not influence the effective loop area of the SQUID any more, the performance of the SQUID can be improved by independently regulating and controlling the thickness of the 3D nanometer bridge junction, the inhibition effect of a
magnetic field on the superconducting characteristic of the 3D nanometer bridge junction is greatly weakened, and in addition, the SQUID probe can be applied to a large scale. The SQUID superconducting loop with the minimum
line width of 10nm can be prepared by combining the
electron beam
lithography technology with higher precision, the area of the SQUID superconducting loop can be greatly reduced, and the spin sensitivity is improved, so that higher spatial resolution can be realized during scanning
magnetic imaging.