Josephson junctions and process for making same

A Josephson junction comprising:

• a substrate;
• a first layer of superconducting material;
• a second layer of superconducting material transversely overlaid on the first layer with an insulating layer interposed therebetween wherein the insulating layer is an oxide of a substance having proximity effect for the superconducting material of the first and second layers;
• and
• the insulating layer including a reduced oxygen-concentrated area in contact with each of the first and second layers so as to function as weak link therebetween.

A Josephson junction comprising:

• a substrate;
• a first layer of superconducting material having a lengthwise slanted side;
• a second layer of superconducting material having a lengthwise slanted side overlaid on the first layer with an insulating layer interposed therebetween such that the slanted sides of the first and second layers intersect each other, wherein the insulating layer is an oxide of the superconducting material;
• and
• wherein the insulating layer includes a reduced oxygen-concentrated area adjacent to an intersection thereof with the slanted side of the second layer, the reduced oxygen-concentrated area being in contact with each of the first and second layers so as to function as weak link therebetween.

A Josephson junction comprising:

• a substrate;
• a first layer of superconducting material having a lengthwise slanted side;
• a second layer of superconducting material having a lengthwise slanted side overlaid on the first layer with an insulating layer interposed therebetween such that the slanted sides of the first and second layers intersect each other, wherein the insulating layer is an oxide of a substance having proximity effect for the superconducting material of the first and second layers;
• and
• wherein the insulating layer includes a reduced oxygen-concentrated area adjacent to an intersection thereof with the slanted side of the second layer, the reduced oxygen-concentrated area being in contact with each of the first and second layers so as to function as weak link therebetween.