US4366494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Josephson junction and a method of making the same
Assignee: National Institute of Advanced Industrial Science and Technology
•
Filing: 1980-05-20
•
Granted: 1982-12-28
•
Expires: 2000-05-20
Abstract
Abstract Disclosed is an improved Josephson junction comprising a superconductor-separator-superconductor laminar depositions on a substrate, the overlying and underlying superconductor layers being laid offset to each other, and a weak link extending from one of the superconductor layers to the other across the thickness of the intervenient separator. A triple layer superconducting device according to this invention has as short barrier length and as low capacitance as possible, and is characteristic of a large product of junction resistance and critical current. Also, the geometrical configuration of the device is most appropriate for the purpose of massproduction.
Inventors
- 👤 Hiroshi Ohta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:45
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/10; H10N60/12; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/873; Y10S505/874
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
69 words
A superconducting device comprising a laminar body including first and second superconductor layers, an insulative spacer layer therebetween and a conductive junction extending between said first and second superconductor layers and across the thickness of the insulative spacer layer and said first and second superconductor layers being offset and superposed with respect to each other such that only a portion of each of said superconductor layers overly each other.
Claim 2
Dependent Claim
69 words
A superconducting device comprising a laminar body including first and second superconductor layers, an insulative spacer layer therebetween and a conductive junction extending between said first and second superconductor layers and across the thickness of the insulative spacer layer and said first and second superconductor layers being offset and superposed with respect to each other such that only a portion of each of said superconductor layers overly each other.
Claim 3
Dependent Claim
20 words
A superconducting device according to claim 1 further comprising a conductive protecting bridge extending parallel and shunting said conductive junction.
Claim 4
Dependent Claim
41 words
A superconducting device according to claim 1 wherein said insulative spacer layer is a semiconductor material doped with impurities providing a resistivity layer having a low resistivity at room temperature and a high resistivity layer at the temperature of liquid helium.
Claim 5
Dependent Claim
34 words
A superconducting device according to claims 1, 2 or 3, wherein said conductive junction is of a material selected from the group consisting of a superconductor, a normal metal, a semimetal, and a semiconductor.
Claim 6
Dependent Claim
37 words
A superconducting device according to claim 4 wherein said first and second superconductor layers are of a superconductor material selected from the group consisting of Nb, Ta, La, Pb, Sn, In, al, alloy superconductors and compound superconductors.
Claim 7
Dependent Claim
40 words
A superconducting device comprising a laminar body including first and second superimposed superconductor layers, an insulative spacer layer therebetween and a conductive junction extending between said first and second superconductor layers and across the thickness of the insulative spacer layer.
Claim 8
Dependent Claim
40 words
A superconducting device comprising a laminar body including first and second superimposed superconductor layers, an insulative spacer layer therebetween and a conductive junction extending between said first and second superconductor layers and across the thickness of the insulative spacer layer.
Claim 9
Dependent Claim
20 words
A superconducting device according to claim 6 further comprising a conductive protecting bridge extending parallel and shunting said conductive junction.
Claim 10
Dependent Claim
33 words
A superconducting device according to claim 6 or 7 wherein said conductive junction is of a material selected from the group consisting of a superconductor, a normal metal, a semimetal, and a semiconductor.
Claim 11
Dependent Claim
37 words
A superconducting device according to claim 8 wherein said first and second superconductor layers are of a superconductor material selected from the group consisting of Nb, Ta, La, Pb, Sn, In, Al, alloy superconductors and compound superconductors.
Claim 12
Dependent Claim
121 words
A superconducting device comprising a laminar body including at least first, second and third superconductor layers an insulative spacer layer disposed between said third layer and said first and second layers, a first conductive junction extending between said third layer and said first layer, a second conductive junction extending between said third layer and said second layer, said first and said second conductive junctions extending across the thickness of said insulative spacer layer, said third layer being disposed on said insulative spacer layer, said insulative spacer layer being offset and superposed with respect to said first and said second layers such that only a portion of said third superconductor layer overlies a portion of each of the first and second layers.
Claim 13
Dependent Claim
121 words
A superconducting device comprising a laminar body including at least first, second and third superconductor layers an insulative spacer layer disposed between said third layer and said first and second layers, a first conductive junction extending between said third layer and said first layer, a second conductive junction extending between said third layer and said second layer, said first and said second conductive junctions extending across the thickness of said insulative spacer layer, said third layer being disposed on said insulative spacer layer, said insulative spacer layer being offset and superposed with respect to said first and said second layers such that only a portion of said third superconductor layer overlies a portion of each of the first and second layers.
Claim 14
Dependent Claim
17 words
A superconducting device as set forth in claim 10 wherein the conductive junctions form a series connection.
Claim 15
Dependent Claim
31 words
A superconducting device according to claim 10 wherein said conductive junctions are of a material selected from the group consisting of a superconductor, a normal metal, a semimetal, and a semiconductor.
Claim 16
Dependent Claim
38 words
A superconducting device according to claim 10 wherein said first, second and third superconductor layers are of a superconductor material selected from the group consisting of Nb, Ta, La, Pb, Sn, In, Al, alloy superconductors and compound superconductors.
Claim 17
Dependent Claim
115 words
A superconducting device comprising a laminar body including at least one set of semiconductor layers, each said set including a pair of first superconductor layers and a second superconductor layer, at least one insulative spacer layer disposed between the first pair of layers and said second layer, and conductive junctions extending between said second layer and each layer of said pair of superconductor layers and across the thickness of the insulative spacer layer and said second superconductor layer being offset and superposed with respect to each layer of said pair of superconductor layers such that only a portion of said second superconductor layer overlies a portion of each layer of said pair of superconductor layers.
Claim 18
Dependent Claim
115 words
A superconducting device comprising a laminar body including at least one set of semiconductor layers, each said set including a pair of first superconductor layers and a second superconductor layer, at least one insulative spacer layer disposed between the first pair of layers and said second layer, and conductive junctions extending between said second layer and each layer of said pair of superconductor layers and across the thickness of the insulative spacer layer and said second superconductor layer being offset and superposed with respect to each layer of said pair of superconductor layers such that only a portion of said second superconductor layer overlies a portion of each layer of said pair of superconductor layers.
Claim 19
Dependent Claim
46 words
A superconducting device as set forth in claim 14 further including a plurality of said sets of semiconductor layers, each set being spaced from the other along a longitudinal axis and the conductive junctions of each set being connected to form a series of Josephson junctions.
Claim 20
Dependent Claim
104 words
A superconducting device as set forth in claim 15 further including a second insulative layer and a further second superconductor layer on said second insulative layer, said second insulative layer being disposed between one of said pair of first superconductor layers of adjacent longitudinally spaced sets and overlying a portion of each said one of said pair of first superconductor layers, and, further a conductive junction extending between said further layer on said second insulative layer and each said one of said pair of first superconductor layers, said further conductive junction forming a series connection with said conductive junctions of said longitudinally spaced sets.
Claim 21
Dependent Claim
23 words
A superconducting device according to claim 10 or 14 further comprising a conductive protecting bridge extending parallel and shunting each said conductive junctions.
Claim 22
Dependent Claim
31 words
A superconducting device according to claim 14 wherein said conductive junctions are of a material selected from the group consisting of a superconductor, a normal metal, a semimetal, and a semiconductor.
Claim 23
Dependent Claim
34 words
A superconducting device according to claim 18 wherein said superconductor layers are of a superconductor material selected from the group consisting of Nb, Ta, La, Pb, Sn, In, Al, alloy superconductors and compound superconductors.
Claim 24
Dependent Claim
39 words
A superconducting device as set forth in claims 1, 6, 10 or 14 wherein the thickness of the insulative spacer layer is less that 100 A, thereby forming a Josephson junction having a barrier length less than 100 A.
Claim 25
Dependent Claim
56 words
A superconducting device according to claims 1, 6, 10 or 14 wherein the superconductor layers and insulative layer are of geometrical shape and the center of said insulative layer and a superconductor layer disposed to overlie said insulative layer are offset with respect to the center of a superconductor layer disposed to underlie said insulative layer.
Claim 26
Dependent Claim
13 words
A superconducting device according to claim 21 wherein said geometrical shapes are circular.
Claim 27
Dependent Claim
13 words
A superconducting device according to claim 21 wherein said geometric shapes are rectangular.
Claim 28
Dependent Claim
39 words
A superconducting device according to claim 21 wherein said insulative layer is disposed under the portion of the overlying superconductor layer and only slightly beyond the edges of that portion of the superconductor layer superposed over another superconductor layer.
Claim 29
Dependent Claim
17 words
A superconductor device according to claim 24 wherein said geometrical shapes of superposed superconducting layers are different.
Claim 30
Dependent Claim
25 words
A superconductor device according to claim 25 wherein one of the superconductor layers is rectangular in shape and the other superconductor layer is triangularly shaped.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-27 | 1986-06-28 | 1986-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-27 | 1990-06-28 | 1990-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-27 | 1994-06-28 | 1994-12-28 | $7700.00 | Window Closed / Lapsed |