US4768069A
Expired / Lapsed
US
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Superconducting Josephson junctions
Assignee: Northrop Grumman Corp
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Filing: 1987-03-23
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Granted: 1988-08-30
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Expires: 2007-03-23
Abstract
Abstract Disclosed is a superconducting Josephson junction which comprises a layer of niobium nitride on a substrate, an epitaxial layer of a pseudo-binary compound on the layer of niobium nitride, where the pseudo-binary compound has the composition about 3 atomic percent MgO--about 97 atomic percent CaO, to about 97 atomic percent MgO--about 3 atomic percent CaO, and an epitaxial layer of niobium nitride on the layer of pseudo-binary compound. Also disclosed is a method of making a Josephson junction by depositing a layer of niobium nitride onto a suitable substrate, depositing an expitaxial layer of a pseudo-binary compound onto the layer of niobium nitride, where the pseudo-binary compound has a composition of about 3 atomic percent MgO--about 97 atomic percent CaO, to about 97 atomic percent MgO--about 3 atomic percent CaO, and depositing an epitaxial layer of niobium nitride onto the layer said pseudo-binary compound.
Inventors
- 👤 John J. Talvacchio
- 👤 Alexander I. Braginski
- 👤 Michael A. Janocko
- 👤 John R. Gavaler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:46
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/01; H10N60/0912; H10N60/10; H10N60/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
69 words
A superconducting Josephson junction comprising: (A) a layer of NbN on a substrate; (B) a solid solution of an epitaxial layer of a pseudo-binary compound on said layer of NbN, said solid solution lying between about 3 atomic % MgO and 97 atomic % CaO, and about 97 atomic % MgO and 3 atomic % CaO; and (C) an epitaxial layer of NbN on said layer of pseudo-binary compound.
Claim 2
Dependent Claim
69 words
A superconducting Josephson junction comprising: (A) a layer of NbN on a substrate; (B) a solid solution of an epitaxial layer of a pseudo-binary compound on said layer of NbN, said solid solution lying between about 3 atomic % MgO and 97 atomic % CaO, and about 97 atomic % MgO and 3 atomic % CaO; and (C) an epitaxial layer of NbN on said layer of pseudo-binary compound.
Claim 3
Dependent Claim
18 words
A junction according to claim 1 wherein said substrate is sapphire having a (1120) or a (0001) orientation.
Claim 4
Dependent Claim
15 words
A junction according to claim 1 wherein said substrate is MgO having a (100) orientation.
Claim 5
Dependent Claim
20 words
A junction according to claim 1 wherein layers (A) and (C) are each about 400 to about 5000 Angstroms thick.
Claim 6
Dependent Claim
16 words
A junction according to claim 1 wherein said layer of NbN are both single crystal layers.
Claim 7
Dependent Claim
107 words
A superconducting Josephson junction comprising: (A) a substrate selected from the group consisting of single crystal MgO and single crystal sapphire; (B) a layer of NbN about 400 to about 5000 Angstroms thick on said substrate; (C) a layer of epitaxial single crystal pseudobinary compound on said layer of NbN about 5 to about 25 Angstroms thick, having a composition that comprises about 78 atomic % MgO and about 22 atomic % CaO, to about 65 atomic % MgO and about 35 atomic % CaO; and (D) a layer of epitaxial NbN about 400 to about 5000 Angstroms thick on said layer of single crystal pseudo-binary compound.
Claim 8
Dependent Claim
107 words
A superconducting Josephson junction comprising: (A) a substrate selected from the group consisting of single crystal MgO and single crystal sapphire; (B) a layer of NbN about 400 to about 5000 Angstroms thick on said substrate; (C) a layer of epitaxial single crystal pseudobinary compound on said layer of NbN about 5 to about 25 Angstroms thick, having a composition that comprises about 78 atomic % MgO and about 22 atomic % CaO, to about 65 atomic % MgO and about 35 atomic % CaO; and (D) a layer of epitaxial NbN about 400 to about 5000 Angstroms thick on said layer of single crystal pseudo-binary compound.
Claim 9
Dependent Claim
22 words
A junction according to claim 6 wherein said layers of single crystal NbN are each about 1500 to about 2500 Angstroms thick.
Claim 10
Dependent Claim
15 words
A junction according to claim 6 wherein said substrate is MgO having a (100) orientation.
Claim 11
Dependent Claim
18 words
A junction according to claim 6 wherein said substrate is sapphire having a (1120) or a (0001) orientation.
Claim 12
Dependent Claim
16 words
A junction according to claim 6 wherein said layers of NbN are both single crystal layers.
Claim 13
Dependent Claim
15 words
A junction according to claim 6 wherein said layers of NbN are both polycrystalline layers.
Claim 14
Dependent Claim
15 words
A superconducting integrated circuit comprising an array of electrically connected junctions according to claim 6.
Claim 15
Dependent Claim
16 words
A superconducting processor comprising an multiplicity of electrically connected superconducting integrated circuits according to claim 12.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-30 | 1992-02-29 | 1992-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-30 | 1996-02-29 | 1996-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-30 | 2000-02-29 | 2000-08-30 | $7700.00 | Window Closed / Lapsed |