US3904889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Superconductive logic circuit utilizing Josephson tunnelling devices
Assignee: International Business Machines Corp
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Filing: 1973-06-29
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Granted: 1975-09-09
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Expires: 1993-06-29
Abstract
Abstract A logic circuit utilizing Josephson tunnelling devices capable of providing a logical OR or NOR indication in a multi-phase time application is provided. A first current flows through a superconducting circuit having a first and second parallel branch. A plurality of Josephson devices are connected in series in the first branch of the superconductive circuit and a single Josephson device is located in the second branch of the circuit. A control means associated with the single Josephson device is operated at a first phase time for switching the device to its finite voltage state and, accordingly, causing the first current to flow through the first branch of the circuit. Further control means are associated with the plurality of Josephson devices in the first branch to cause one or more of the devices to switch to its finite voltage state at phase two time thereby causing the first current to switch back to the second branch. Output circuit means are associated with each branch of the circuit operable at phase three time for producing an output indicative of the current flow in the branch.
Inventors
- 👤 Harvey C Hamel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:40
CPC Classifications
H; H03; H03K; H03K19/00; H03K19/02; H03K19/195; H03K19/1952; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/856; Y10S505/857; Y10S505/858
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
291 words
An apparatus using Josephson tunnelling devices in a multiphase time sequence comprising: a superconducting circuit having a first and second parallel branch; a first current source connected in parallel to said first and second branch for providing a first current therethrough; a plurality of Josephson tunnelling devices connected in series in said first branch of said superconductive circuit each having first and second electrodes and a tunnel barrier therebetween across which Josephson current can tunnel, said first and second electrodes and said barrier of each Josephson tunnelling device being connected in series; a single Josephson tunnelling device located in said second branch of said superconducting circuit; a first control conductor located adjacent said single Josephson tunnelling device, electrical pulses in said first control conductor at phase one time producing magnetic fields which couple to said single Josephson tunnelling device causing the Josephson tunnelling device to switch to its finite voltage state thereby causing said first current to flow through said first branch of said circuit; a plurality of second control conductors, one associated with each of said plurality of Josephson tunnelling devices, electrical pulses in said conductors at phase two time producing magnetic fields which couple to said adjacent one of said plurality of Josephson tunnelling devices causing it to switch to its finite voltage state thereby causing said first current to flow through said second branch of said circuit; and a first and second output Josephson tunnelling device, the first one switched to its finite voltage state when none of the plurality of Josephson tunnelling devices is in its finite voltage state and the second one switched to its finite voltage state when one or more of said first plurality of Josephson tunnelling devices is in its finite voltage state.
Claim 2
Independent Claim
291 words
An apparatus using Josephson tunnelling devices in a multiphase time sequence comprising: a superconducting circuit having a first and second parallel branch; a first current source connected in parallel to said first and second branch for providing a first current therethrough; a plurality of Josephson tunnelling devices connected in series in said first branch of said superconductive circuit each having first and second electrodes and a tunnel barrier therebetween across which Josephson current can tunnel, said first and second electrodes and said barrier of each Josephson tunnelling device being connected in series; a single Josephson tunnelling device located in said second branch of said superconducting circuit; a first control conductor located adjacent said single Josephson tunnelling device, electrical pulses in said first control conductor at phase one time producing magnetic fields which couple to said single Josephson tunnelling device causing the Josephson tunnelling device to switch to its finite voltage state thereby causing said first current to flow through said first branch of said circuit; a plurality of second control conductors, one associated with each of said plurality of Josephson tunnelling devices, electrical pulses in said conductors at phase two time producing magnetic fields which couple to said adjacent one of said plurality of Josephson tunnelling devices causing it to switch to its finite voltage state thereby causing said first current to flow through said second branch of said circuit; and a first and second output Josephson tunnelling device, the first one switched to its finite voltage state when none of the plurality of Josephson tunnelling devices is in its finite voltage state and the second one switched to its finite voltage state when one or more of said first plurality of Josephson tunnelling devices is in its finite voltage state.
Claim 3
Dependent Claim
29 words
The apparatus of claim 1, wherein said first and second branch circuits of said superconducting circuit are comprised of stripline connected to the electrodes of said Josephson tunnelling devices.
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) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |