US3676718A
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Supercurrent structures utilizing mobil flux vortices
Assignee: AT&T Inc
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Filing: 1971-03-26
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Granted: 1972-07-11
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Expires: 1991-03-26
Abstract
Abstract A supercurrent logic structure of extended dimensions is capable of sustaining a plurality of trapped magnetic field vortices each of which supports one flux quantum. Such a vortex prefers to position itself in a region such that a local minimum of the sum of the magnetic energy plus the Josephson coupling energy is established. A variety of ways to create such preferred regions are disclosed. A vortex is moved from one such region to another in shift register fashion by applying a force thereto as, for example, by applying a local current or magnetic field near to the vortex.
Inventors
- 👤 Philip Warren Anderson
- 👤 Robert Carr Dynes
- 👤 Theodore Alan Fulton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:30
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/32; G11C11/00; G11C11/21; G11C11/44; H; H10; H10N; H10N60/00; H10N60/10; H10N60/12; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/856; Y10S505/857; Y10S505/865
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
98 words
Supercurrent apparatus comprising a weak-link supercurrent structure, creating means for creating in said structure a plurality of magnetic field vortices each characterized by a circulating supercurrent and a flux quantum induced by said supercurrent, means of establishing in said structure preferred locations about each of which a vortex distributes itself so that a local minimum of the sum of the total magnetic energy plus the Josephson coupling energy is created with respect to such vortex, and control means for causing selected ones of said vortices to propagate in said structure from one of said preferred locations to another.
Claim 2
Dependent Claim
98 words
Supercurrent apparatus comprising a weak-link supercurrent structure, creating means for creating in said structure a plurality of magnetic field vortices each characterized by a circulating supercurrent and a flux quantum induced by said supercurrent, means of establishing in said structure preferred locations about each of which a vortex distributes itself so that a local minimum of the sum of the total magnetic energy plus the Josephson coupling energy is created with respect to such vortex, and control means for causing selected ones of said vortices to propagate in said structure from one of said preferred locations to another.
Claim 3
Dependent Claim
63 words
The apparatus of claim 1 wherein said preferred locations are centered in regions separated by a distance S which to a first approximation satisfies the relationship LIc Phi o where L is the self-inductance of a circulating supercurrent path, Phi o is the flux quantum supported by the circulating supercurrent and Ic is the net critical current of a region of length S.
Claim 4
Dependent Claim
50 words
The apparatus of claim 1 wherein said control means comprises means for applying control current in control regions near to each of said preselected vortices and in a direction opposite to the flow of supercurrent in said control regions so that said preselected vortices propagate away from said control regions.
Claim 5
Dependent Claim
49 words
The apparatus of claim 1 wherein said control means comprises means for applying control current in control regions near to each of said preselected vortices and in the same direction as the flow of supercurrent in said control regions so that said preselected vortices propagate toward said control region.
Claim 6
Dependent Claim
69 words
The apparatus of claim 1 wherein said weak-link structure is elongated, said creating means comprises a current source connected to one end of said structure, and said control means comprises means for selectively applying control current along the elongated dimension of said structure at spaced points near to said preferred locations so that preselected ones of said vortices are made to move toward the other end of aid structure.
Claim 7
Dependent Claim
26 words
The apparatUs of claim 5 including utilization means connected to the other end of said structure to detect said vortices as each reaches said other end.
Claim 8
Dependent Claim
40 words
The apparatus of claim 6 wherein the output of said creating means comprises a pulse code modulated train of current pulses, each pulse being separated by a blanking interval, and said control means is turned on during said blanking intervals.
Claim 9
Dependent Claim
39 words
The apparatus of claim 7 wherein the current from said control means is applied sequentially to each of said spaced points beginning with the point nearest to said other end and ending with the point nearest said one end.
Claim 10
Dependent Claim
22 words
The apparatus of claim 7 wherein the current from said control means is applied substantially simultaneously to each of said spaced points.
Claim 11
Dependent Claim
21 words
The apparatus of claim 1 wherein each of said preferred locations is a region in which the critical supercurrent is zero.
Claim 12
Dependent Claim
68 words
The apparatus of claim 10 including a pair of superconductive layers, a nonsuperconductive layer contiguous with and separating said superconductive layers, said nonsuperconductive layer having a plurality of apertures extending therethrough between said superconductive layers, said apertures forming said preferred locations and the remaining portions of said nonsuperconductive layer in conjunction with said superconductive layers contiguous therewith forming a plurality of said weak-link regions electrically connected in parallel.
Claim 13
Dependent Claim
22 words
The apparatus of claim 11 wherein said nonsuperconductive layer comprises a material selected from the group consisting of insulators and normal metal.
Claim 14
Dependent Claim
87 words
The apparatus of claim 10 including a pair of superconductive layers, a nonsuperconductive layer contiguous with and separating said superconductive layers, said nonsupercondutive layer having a plurality of separated first regions of thickness effective to prevent supercurrent tunneling therethrough and a plurality of second regions interleaving said first regions and of thickness effective to permit supercurrent tunneling therethrough, said first regions constituting said preferred locations in which the critical supercurrent is substantially zero and said second regions constituting a plurality of weak-link regions electrically connected in parallel.
Claim 15
Dependent Claim
22 words
The apparatus of claim 13 wherein said nonsuperconductive layer comprises a material selected from the group consisting of insulators and normal metals.
Claim 16
Dependent Claim
125 words
The apparatus of claim 10 including a first superconductive layer in the form of a strip having a plurality of first appendages of the same material as said strip extending therefrom, plurality of nonsuperconductive layers, one formed on at least a portion of each of said first appendages, a second superconductive layer contacting each of said nonsuperconductive layers, thereby forming a plurality of superconducting loops each of which includes a pair of weak-link regions electrically connected in parallel, each of said loops being adapted so that to a first approximation LIc Phi o where L is the self inductance of the loop in which a supercurrent flows supporting a flux quantum Phi o, and Ic is the critical current of each of said weak-link regions.
Claim 17
Dependent Claim
22 words
The apparatus of claim 15 where said nonsuperconductive layers comprise a material selected from the group consisting of insulators and normal metals.
Claim 18
Dependent Claim
20 words
The apparatus of claim 16 including a separate resistive shunt electrically connected in parallel with each of said weak-link regions.
Claim 19
Dependent Claim
64 words
The apparatus of claim 17 wherein said creating means comprises a current source connected between a first one of said first appendages and said second layer, said control means includes means for applying a current between said second layer and selected ones of said other first appendages, and including utilization means connected between a different one of said first appendages and said second layer.
Claim 20
Dependent Claim
17 words
The appAratus of claim 18 including a separate weak-link magnetometer magnetically coupled to each of said loops.
Claim 21
Dependent Claim
96 words
The apparatus of claim 19 wherein said first appendages are located on one side of said strip and said magnetometers each comprise a pair of second appendages extending from the other side of said strip, opposite one of said loops, a plurality of nonsuperconductive layers, one formed on a portion of each of said second appendages, a third superconductive layer contacting each of said nonsuperconductive layers thereby forming a pair of weak-link regions electrically connected in parallel, and means for detecting changes induced in the critical supercurrent of each of said latter pairs of weak-link regions.
Claim 22
Dependent Claim
104 words
The apparatus of claim 1 including a pair of elongated superconductive layers, an elongated nonsuperconductive third layer of substantially uniform thickness contiguous with and disposed between said superconductive layers, thereby forming an elongated multilayered structure, means for applying along said third layer a localized magnetic field at a plurality of points equally spaced by a distance of approximately twice the Josephson penetration depth and in a direction substantially parallel to said third layer, thereby defining said preferred locations about which said vortices prefer to distribute themselves, said magnetic field being applied in magnetic sense opposite to that of said vortex in said third layer.
Claim 23
Dependent Claim
56 words
The apparatus of claim 21 wherein said creating means comprises a current source connected across said superconductive layer at one end of said structure, and said control means comprises means for selectively applying a control current near to predetermined ones of said vortices so that said predetermined vortices propagate toward the other end of said structure.
Claim 24
Dependent Claim
30 words
The apparatus of claim 22 including utilization means connected across said superconductive layers at the other end of said structure to detect said vortices as each reaches said other end.
Claim 25
Dependent Claim
22 words
The apparatus of claim 23 wherein said nonsuperconductive layer comprises a material selected from the group consisting of insulators and normal metals.
Claim 26
Dependent Claim
58 words
The apparatus of claim 1 including a first portion in which the critical supercurrent is substantially uniform and nonzero, contiguous with said first portion, a second portion in which the critical supercurrent is substantially zero and which is characterized by a variable self-inductance per unit length as measured in a direction parallel to the direction of vortex propagation.
Claim 27
Dependent Claim
23 words
The apparatus of claim 25 wherein the width of said second portion undulates along a face parallel to said direction of vortex propagation.
Claim 28
Dependent Claim
14 words
The apparatus of claim 26 wherein the width of said second portion undulates periodically.
Claim 29
Dependent Claim
111 words
The apparatus of claim 27 wherein said first portion comprises a first pair of elongated superconductive layers, a first elongated nonsuperconductive layer of substantially uniform thickness effective to permit the flow of supercurrent therethrough, said first nonsuperconductive layer being contiguous with and disposed between said first pair of superconductive layers, and said second portion comprises a second pair of superconductive layers, a second elongated nonsuperconductive layer of substantially uniform thickness effective to prevent the flow of supercurrent therethrough, said second nonsuperconductive layer being contiguous with and disposed between said second pair of superconductive layers, one elongated face of said first portion being contiguous with one elongated face of said second portion.
Claim 30
Dependent Claim
21 words
The apparatus of claim 28 wherein the width of said second portion undulates in the shape of a periodic square wave.
Claim 31
Dependent Claim
58 words
The apparatus of claim 28 wherein said creating means comprises a current source connected across said first pair of superconductive layers at one end of said strucTure, and said control means comprises means for selectively applying a control current near to predetermined ones of said vortices so that said predetermined vortices propagate toward the other end said structure.
Claim 32
Dependent Claim
33 words
The apparatus of claim 30 including utilization means connected across said first pair of superconductive layers at the other end of said structure to detect said vortices as each reaches said other end.
Claim 33
Dependent Claim
22 words
The apparatus of claim 31 wherein said nonsuperconductive layers comprise a material selected from the group consisting of insulators and normal metals.
Claim 34
Dependent Claim
65 words
For use in weak-link supercurrent apparatus, a structure comprising a plurality of weak-link supercurrent regions electrically connected in parallel to form a plurality of closed circuit paths coupled to one another, adjacent ones of said regions being uniformly separated by a distance S effective to sustain in selected ones of said paths a circulating supercurrent which supports a single magnetic flux quantum linking said path.
Claim 35
Dependent Claim
65 words
For use in weak-link supercurrent apparatus, a structure comprising a plurality of weak-link supercurrent regions electrically connected in parallel to form a plurality of closed circuit paths coupled to one another, adjacent ones of said regions being uniformly separated by a distance S effective to sustain in selected ones of said paths a circulating supercurrent which supports a single magnetic flux quantum linking said path.
Claim 36
Dependent Claim
59 words
The structure of claim 33 wherein said distance S is selected so that to a first approximation the following relationship is satisfied LIc Phi o where L is the self-inductance of each of said paths, Phi o is the flux quantum supported by each circulating supercurrent and Ic is the net critical current of a region of length S.
Claim 37
Dependent Claim
53 words
The structure of claim 34 including a pair of superconductive layers, a nonsuperconductive layer separating said superconductive layers, said nonsuperconductive layer having a plurality of apertures extending therethrough between said superconductive layers, thereby defining between said apertures a plurality of spaced nonsuperconductive regions which constitute said plurality of weak-link regions connected in parallel.
Claim 38
Dependent Claim
66 words
The structure of clam 34 including a pair of superconductive layers a nonsuperconductive layer separating said superconductive layers, said nonsuperconductive layer having a plurality of spaced first regions of thickness effective to prevent supercurrent tunneling therethrough and interleaving said first regions a plurality of second regions of thickness effective to permit supercurrent tunneling therethrough, said second regions constituting said plurality of weak-link regions connected in parallel.
Claim 39
Dependent Claim
66 words
The structure of clam 34 including a pair of superconductive layers a nonsuperconductive layer separating said superconductive layers, said nonsuperconductive layer having a plurality of spaced first regions of thickness effective to prevent supercurrent tunneling therethrough and interleaving said first regions a plurality of second regions of thickness effective to permit supercurrent tunneling therethrough, said second regions constituting said plurality of weak-link regions connected in parallel.
Claim 40
Dependent Claim
73 words
For use in weak-link supercurrent apparatus for guiding the propagation of magnetic flux vortices in a first direction, a structure comprising a first portion in which the critical supercurrent is substantially uniform and nonzero, contiguous with said first portion, a second portion in which the critical supercurrent is substantially zero and which is characterized by a variable self-inductance per unit length as measured in a direction parallel to the direction of vortex propagation.
Claim 41
Dependent Claim
73 words
For use in weak-link supercurrent apparatus for guiding the propagation of magnetic flux vortices in a first direction, a structure comprising a first portion in which the critical supercurrent is substantially uniform and nonzero, contiguous with said first portion, a second portion in which the critical supercurrent is substantially zero and which is characterized by a variable self-inductance per unit length as measured in a direction parallel to the direction of vortex propagation.
Claim 42
Dependent Claim
23 words
The apparatus of claim 37 where the width of said second portion undulates along a face parallel to said direction of vortex propagation.
Claim 43
Dependent Claim
14 words
The apparatus of claim 38 wherein the width of said second portion undulates periodically.
Claim 44
Dependent Claim
111 words
The apparatus of claim 39 wherein said first portion comprises a first pair of elongated superconductive layers, a first elongated nonsuperconductive layer of substantially uniform thickness effective to permit the flow of supercurrent therethrough, said first nonsuperconductive layer being contiguous with and disposed between said first pair of superconductive layers, and said second portion comprises a second pair of superconductive layers, a second elongated nonsuperconductive layer of substantially uniform thickness effective to prevent the flow of supercurrent therethrough, said second nonsuperconductive layer being contiguous with and disposed between said second pair of superconductive layers, one elongated face of said first portion being contiguous with one elongated face of said second portion.
Claim 45
Dependent Claim
21 words
The apparatus of claim 40 whErein the width of said second portion undulates in the shape of a periodic square wave.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |