Fabrication method of superconducting quantum interference device constructed from short weak links with ultrafine metallic wires

A superconducting quantum interference device (DC-SQUID) comprising:

• two weak link type Josephson elements interconnected in a loop;
• each of said two weak link type Josephson elements comprising an edge-sandwich of a base electrode layer, a counterelectrode layer and an insulating film, the insulating film having opposite major surfaces defining a thickness thereof and being disposed between and interconnecting the base electrode layer and the counterelectrode layer, said insulating thin film having pinholes therein;
• and
• a nanometric bridge comprising field evaporated material of one of the base electrode layer and the counterelectrode layer transferred into and filling the pinholes in, and extending through the insulating thin film in a direction of the thickness thereof and between the opposite major surfaces thereof and forming a superconductive link between the base electrode layer and the counterelectrode layer.

A superconducting quantum interference device (DC-SQUID) comprising:

• two weak link type Josephson elements interconnected in a loop;
• each of said two weak link type Josephson elements comprising an edge-sandwich of a base electrode layer, a counter electrode layer and an insulating film, the insulating film having opposite major surfaces defining a thickness thereof and being disposed between and structurally interconnecting the base electrode layer and the counterelectrode layer, said insulating thin film having pinholes therein;
• and
• plural metallic conductive paths extending through the pinholes in the insulating thin film, in a direction of the thickness thereof, and forming a superconductive link between the base electrode layer and the counterelectrode layer.

A super conducting quantum interference device (DC-SQUID) comprising:

• two weak link type Josephson elements interconnected in a loop;
• each of said two weak link type Josephson elements comprising:
• an insulating base support structure having a major upper surface,
• a base electrode layer formed on the major upper surface of the insulating base support structure and having an upper surface parallel to the upper major surface of the insulating base support structure and a generally planar end face disposed at an oblique angle relatively to the upper major surface of the insulating base support structure,
• a sputtered, insulating thin film having a first major surface formed on the oblique end face of the base electrode layer and an opposite, second major surface substantially parallel thereto and having pinholes therein extending between the first and second major surfaces thereof,
• a counterelectrode layer formed on the second major surface of the sputtered insulating film, and
• field evaporated material of one of the base electrode layer and the counterelectrode layer being transferred into and filling the pinholes and thereby forming a superconductive link extending through the insulating film and interconnecting the base electrode layer and the counterelectrode layer.