US4025844A
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Granular superconducting quantum interference device and apparatus including same
Assignee: Ramot at Tel Aviv University Ltd
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Filing: 1975-06-23
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Granted: 1977-05-24
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Expires: 1995-06-23
Abstract
Abstract Superconducting quantum interference devices (SQUID's) are described including two superconductor pathways connected together by a narrow bridge of a granular superconductor material having a high normal state electrical resistivity of about 10.sup. -4 to 10.sup. -2 ohm-cm. The latter material is preferably a granular superconductor including superconductor grains having a low normal state electrical resistivity embedded in a matrix of a material having a high normal state electrical resistivity. Also described is the use of such devices in linear applications, such as in a magnetometers, and digital applications, such as switches, flip-flops, and memory cells.
Inventors
- 👤 Siegfried Guy Deutscher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:22
CPC Classifications
G; G01; G01R; G01R29/00; G01R33/00; G01R33/02; G01R33/035; G01R33/0354; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/842; Y10S505/843; Y10S505/845; Y10S505/846; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49014
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
41 words
A superconducting quantum interference device characterized in that it includes two superconductor pathways connected together by a narrow bridge of a granular superconductor material having a high normal state electrical resistivity of about 10 - 4 to 10 - 2 ohm-cm.
Claim 2
Dependent Claim
41 words
A superconducting quantum interference device characterized in that it includes two superconductor pathways connected together by a narrow bridge of a granular superconductor material having a high normal state electrical resistivity of about 10 - 4 to 10 - 2 ohm-cm.
Claim 3
Dependent Claim
44 words
The device according to claim 1, wherein said granular superconductor material includes superconductor grains of a size in the order of 30 A having a low normal state electrical resistivity embedded in a matrix of a material having a high normal state electrical resistivity.
Claim 4
Dependent Claim
33 words
The device according to claim 1, wherein the bridge of granular superconductor materials has a thickness of up to 10 - 5 cm, and a width of up to 5.10 - 3 cm.
Claim 5
Dependent Claim
30 words
The device according to claim 1, wherein the superconductor pathways and the granular superconductor bridge connecting them are each in the form of a thin film coated on a substrate.
Claim 6
Dependent Claim
28 words
The device according to claim 4, wherein the substrate is a rod, the superconductor pathways defining a ring with the granular superconductor bridge forming a weak link therein.
Claim 7
Dependent Claim
46 words
The device according to claim 5, wherein the superconductor pathways are also of granular superconductor material having a high normal state electrical resistivity of about 10 - 4 to 10 - 2 ohm-cm., the weak link being defined by a narrow constriction formed in said ring.
Claim 8
Dependent Claim
21 words
The device according to claim 4, wherein the superconductor pathways are of superconductor material having a low normal state electrical resistivity.
Claim 9
Dependent Claim
22 words
The device according to claim 1, wherein said granular superconductor material includes grains of aluminum embedded in a matrix of aluminum oxide.
Claim 10
Dependent Claim
46 words
The device according to claim 8, wherein said granular superconducting material comprises 30%-40% aluminum grains embedded in a matrix of aluminum oxide, the size of the aluminum grains being about 30 A, the normal state resistivity of the granular film being about 10 - 3 ohm-cm.
Claim 11
Dependent Claim
32 words
Measuring apparatus characterized in that it includes a sensor device in accordance with claim 1, wherein the superconductor pathways define a ring, and the granular superconductor bridge constitutes a weak link therein.
Claim 12
Dependent Claim
48 words
The apparatus according to claim 10, wherein said superconductor pathway ring and the granular superconductor weak link therein are in the form of a coating of a granular superconductor on a rod substrate, portions of the coating being removed to form a constriction defining said weak link bridge.
Claim 13
Dependent Claim
13 words
The apparatus according to claim 10, wherein said measuring apparatus is a magnetometer.
Claim 14
Dependent Claim
71 words
A digital element characterized in that it includes the device in accordance with claim 1, wherein the superconductor pathways are of a superconductor material having a low normal state of electrical resistivity, and the granular superconductor bridge constitutes a weak link therein, the apparatus further including means for selectively applying a magnetic field to the granular superconductor bridge to switch same to either the superconductor state or to the normal state.
Claim 15
Dependent Claim
30 words
The digital element according to claim 13, wherein the digital element is a memory cell including a superconductor ring in which the granular superconductor bridge constitutes a switching gate therein.
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) | 1980-05-23 | 1980-11-22 | 1981-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-23 | 1984-11-22 | 1985-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-23 | 1988-11-22 | 1989-05-24 | $7700.00 | Window Closed / Lapsed |