Patent US5831278A successfully refreshed from Google Patents.
US5831278A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three-terminal devices with wide Josephson junctions and asymmetric control lines
Assignee: Silicon Valley Bank Inc
•
Filing: 1996-03-15
•
Granted: 1998-11-03
•
Expires: 2016-03-15
Abstract
Abstract A three-terminal device constructed from a Josephson junction with one or more asymmetric control lines is disclosed. The device is constructed with high temperature superconducting materials. The junction can be a bicrystal, SNS (Superconducting-Normal-Superconducting) or any other type of high temperature superconductor junction. The control line is either a conducting or superconducting material which is electrically isolated from the junction but inductively coupled into the junction. A portion of the control line is approximately directly above the junction and has current which at least partially flows parallel or nonparallel to current flowing across the junction. The control line current alters the magnetic field within the junction which changes the critical current of the junction. The junction is in a superconducting or resistive state depending on whether the bias current of the junction is greater than or less than the control current. Logic gates, including an XOR gate, are formed using this device and one or more control lines.
Inventors
- 👤 Stuart J. Berkowitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:37
CPC Classifications
H; H03; H03K; H03K19/00; H03K19/02; H03K19/195; H03K19/1952; H03K19/20; H03K19/21; H10; H10N; H10N60/00; H10N60/10; H10N60/12; H10N60/124; H10N60/128; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/831; Y10S505/832; Y10S505/856; Y10S505/857; Y10S505/858; Y10S505/859; Y10S505/86; Y10S505/861
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
128 words
A three-terminal device comprising: (a) a substrate; (b) a high temperature superconductor material disposed on said substrate in a pattern of a wide Josephson junction; (c) a bias lead means operatively connected to said high temperature superconductor material for biasing said Josephson junction; (d) at least one conducting means, wherein a portion of said conducting means is directly above or below said Josephson junction, wherein said portion is at least partially capable of carrying a current in a direction parallel to a current flow across said Josephson junction; and (e) an insulating layer between said conducting means and said Josephson junction, said insulating layer being of a thickness such that said conducting means is electrically isolated from said Josephson junction but still magnetically coupled to said Josephson junction.
Claim 2
Dependent Claim
128 words
A three-terminal device comprising: (a) a substrate; (b) a high temperature superconductor material disposed on said substrate in a pattern of a wide Josephson junction; (c) a bias lead means operatively connected to said high temperature superconductor material for biasing said Josephson junction; (d) at least one conducting means, wherein a portion of said conducting means is directly above or below said Josephson junction, wherein said portion is at least partially capable of carrying a current in a direction parallel to a current flow across said Josephson junction; and (e) an insulating layer between said conducting means and said Josephson junction, said insulating layer being of a thickness such that said conducting means is electrically isolated from said Josephson junction but still magnetically coupled to said Josephson junction.
Claim 3
Dependent Claim
15 words
The three-terminal device of claim 1 wherein said Josephson junction is of a bicrystal type.
Claim 4
Dependent Claim
15 words
The three-terminal device of claim 1 wherein said Josephson junction is of an SNS type.
Claim 5
Dependent Claim
20 words
The three-terminal device of claim 1 wherein at least one of said conducting means is directly above said Josephson junction.
Claim 6
Dependent Claim
19 words
The three-terminal device of claim 1 wherein said portion of said conducting means crosses said Josephson junction generally perpendicularly.
Claim 7
Dependent Claim
21 words
The three-terminal device of claim 5 wherein said portion of said conducting means crosses near a center of said Josephson junction.
Claim 8
Dependent Claim
28 words
The three-terminal device of claim 1 further comprising a superconducting ground plane and an insulating layer overlying said ground plane interposed between said substrate and said Josephson junction.
Claim 9
Dependent Claim
80 words
A three terminal device comprising: (a) a wide Josephson junction; (b) bias lead means operatively connected to said Josephson junction for biasing said junction; (c) at least one conducting means directly above or below said Josephson junction, said conducting means being electrically isolated from said Josephson junction but still inductively coupled to said Josephson junction; and (d) wherein said conductive means has a current flow that is at least partially parallel or antiparallel to current flow across said Josephson junction.
Claim 10
Dependent Claim
80 words
A three terminal device comprising: (a) a wide Josephson junction; (b) bias lead means operatively connected to said Josephson junction for biasing said junction; (c) at least one conducting means directly above or below said Josephson junction, said conducting means being electrically isolated from said Josephson junction but still inductively coupled to said Josephson junction; and (d) wherein said conductive means has a current flow that is at least partially parallel or antiparallel to current flow across said Josephson junction.
Claim 11
Independent Claim
101 words
A method of operating the device of claims 1 or 8 comprising: (a) biasing the Josephson junction with a bias current, I b , said bias current being less than the critical current, I c , said critical current being the maximum current at which the Josephson junction remains superconducting; and (b) applying a current to said conducting means to alter said critical current to a new value, I c ', such that either (i) I b <I c ', in which case the device remains superconducting, or (ii) I b >I c ', in which case the device becomes resistive.
Claim 12
Dependent Claim
19 words
The method of claim 9 further comprising the step of providing a dc bias field to the Josephson junction.
Claim 13
Dependent Claim
12 words
A logic gate comprising the three-terminal device of claims 1 or 8.
Claim 14
Dependent Claim
25 words
The logic gate of claim 11 wherein the three-terminal device comprises two conducting means and the logic gate is of the XOR or OR type.
Claim 15
Dependent Claim
12 words
The logic gate of claim 12 wherein there are two conducting means.
Claim 16
Dependent Claim
16 words
The logic gate of claim 13 wherein the two conducting means are proximate to one another.
Claim 17
Dependent Claim
43 words
The logic gate of claim 13 wherein the two conducting means are each attached to separate current sources, said current sources providing current such that a direction of current flow in one conducting means is opposite to that in the other conducting means.
Claim 18
Dependent Claim
46 words
The logic gate of claim 13 wherein the two conducting means are each attached to separate current sources, said current sources providing current such that a direction of current flow in one conducting means is in the same direction as that in the other conducting means.
Claim 19
Dependent Claim
34 words
The logic gate of claim 11 further comprising a bias field means a portion of which is provided above or below said Josephson junction to generate a dc bias field in said Josephson junction.
Claim 20
Dependent Claim
115 words
A multi-terminal device, comprising: (a) a wide Josephson junction including high temperature superconductor material; (b) a bias lead operatively connected to the high temperature superconductor material for biasing the Josephson junction; (c) at least one control line, wherein a portion of the control line is directly above or below the Josephson junction, wherein the portion is at least partially capable of carrying a current in a direction parallel to a current flow across the Josephson junction; and (d) an insulating layer between the control line and the Josephson junction, the insulating layer having a thickness such that the control line is electrically isolated from the Josephson junction but still magnetically coupled to the Josephson junction.
Claim 21
Dependent Claim
115 words
A multi-terminal device, comprising: (a) a wide Josephson junction including high temperature superconductor material; (b) a bias lead operatively connected to the high temperature superconductor material for biasing the Josephson junction; (c) at least one control line, wherein a portion of the control line is directly above or below the Josephson junction, wherein the portion is at least partially capable of carrying a current in a direction parallel to a current flow across the Josephson junction; and (d) an insulating layer between the control line and the Josephson junction, the insulating layer having a thickness such that the control line is electrically isolated from the Josephson junction but still magnetically coupled to the Josephson junction.
Claim 22
Dependent Claim
30 words
The three-terminal device of claim 18, further comprising a substrate with the high temperature superconductor material disposed over the substrate according to a pattern to form the wide Josephson junction.
Claim 23
Dependent Claim
62 words
The multi-terminal device of claim 18, wherein the multi-terminal device comprises at least two control lines each having a portion that is directly above or below the Josephson junction, wherein the portion of each of the at least two control lines is at least partially capable of carrying a current in a direction parallel to a current flow across the Josephson junction.
Claim 24
Dependent Claim
10 words
A logic gate comprising the three-terminal device of claim 18.
Claim 25
Dependent Claim
61 words
The logic gate of claim 21, wherein the logic gate comprises at least two control lines having a portion that is directly above or below the Josephson junction, wherein the portion of each of the at least two control lines is at least partially capable of carrying a current in a direction parallel to a current flow across the Josephson junction.
Claim 26
Dependent Claim
17 words
The logic gate of claim 22, wherein the logic gate is of the XOR or OR type.
Claim 27
Dependent Claim
99 words
A method of operating the device of claim 18 comprising: (a) biasing the Josephson junction with a bias current, I b , the bias current being less than the critical current, I c , the critical current being the maximum current at which the Josephson junction remains superconducting; and (b) applying a current to the control line to alter the critical current to a new value, I c ', such that either (i) I b <I c ', in which case the device remains superconducting, or (ii) I b >I c ', in which case the device becomes resistive.
References Cited (Backward Citations)
US3643237A
Cited
US3758795A
Cited
US3784854A
Cited
US3913027A
Cited
US3886382A
Cited
US3943383A
Cited
US4423430A
Cited
US5106823A
Cited
US5162298A
Cited
US5347143A
Cited
US5696392A
Cited
US5358928A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-11-02 | 2002-05-04 | 2002-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-02 | 2006-05-04 | 2006-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-02 | 2010-05-04 | 2010-11-03 | $7700.00 | Window Closed / Lapsed |