EP0357321A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Superconducting transistor
Assignee: Fujitsu Ltd
•
Filing: 1989-08-22
•
Granted: —
•
Expires: 2009-08-22
Abstract
Abstract A superconducting transistor comprises a superconducting collector layer (1) a first barrier layer (2) provided on the superconducting collector layer (1), a superconducting base layer (3) provided on the first barrier layer (2), a second barrier layer (4) provided on the superconducting base layer (3), and a superconducting emitter layer (5) provided on the second barrier layer (4). All of the layers (1-5) are formed of substances having the same component elements but the composition differs from one layer to the next. The barrier layers (2, 4) have a low carrier concentration and do not have superconducting properties whilst the collector (1), base (3) and emitter (5) layers have a high carrier concentration and exhibit superconducting properties. The superconducting collector layer (1) draws out quasi-particles from the superconducting base layer (3) whilst its carrier concentration is maintained at a level lower than that in metal and at a high level where a superconducting property, is exhibited.
Inventors
- 👤 Hirotaka Tamura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 05:36
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/10; H10N60/128; Y; Y10; Y10S; Y10S505/00; Y10S505/70; Y10S505/701; Y10S505/702
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
262 words
A superconducting transistor comprising: a superconducting collector layer (1) formed of predetermined component elements and having a predetermined composition, a first barrier layer (2) provided on the superconducting collector layer (1), formed of a substance having the same component elements as that of the collector layer (1) but a different composition, said first barrier layer having a low carrier concentration and not exhibiting a superconducting property, a superconducting base layer (3) provided on the first barrier layer (2), formed of a substance having the same component elements as that of said superconducting collector layer (1), having a different composition from that of the first barrier layer (2) a high carrier concentration and exhibiting a superconducting property; a second barrier layer (4) provided on the superconducting base layer (3) formed of a substance having the same component elements as that of the superconducting collector layer (1) but having a different composition from that of the superconducting collector layer (1) a low carrier concentration and not exhibiting a superconducting property, and, a superconducting emitter layer (5) provided on the second barrier layer (4), formed of a substance having the same component elements as that of said superconducting collector (1) but having a different composition from that of the first (2) and second (4) barrier layers, having a high carrier concentration and exhibiting a superconducting property, the superconducting collector layer (1) for drawing out quasi-particles from the superconducting base layer (3) while its carrier concentration is maintained at a level lower than in metal and at a high level where the superconducting property is exhibited.
Claim 2
Dependent Claim
262 words
A superconducting transistor comprising: a superconducting collector layer (1) formed of predetermined component elements and having a predetermined composition, a first barrier layer (2) provided on the superconducting collector layer (1), formed of a substance having the same component elements as that of the collector layer (1) but a different composition, said first barrier layer having a low carrier concentration and not exhibiting a superconducting property, a superconducting base layer (3) provided on the first barrier layer (2), formed of a substance having the same component elements as that of said superconducting collector layer (1), having a different composition from that of the first barrier layer (2) a high carrier concentration and exhibiting a superconducting property; a second barrier layer (4) provided on the superconducting base layer (3) formed of a substance having the same component elements as that of the superconducting collector layer (1) but having a different composition from that of the superconducting collector layer (1) a low carrier concentration and not exhibiting a superconducting property, and, a superconducting emitter layer (5) provided on the second barrier layer (4), formed of a substance having the same component elements as that of said superconducting collector (1) but having a different composition from that of the first (2) and second (4) barrier layers, having a high carrier concentration and exhibiting a superconducting property, the superconducting collector layer (1) for drawing out quasi-particles from the superconducting base layer (3) while its carrier concentration is maintained at a level lower than in metal and at a high level where the superconducting property is exhibited.
Claim 3
Dependent Claim
21 words
A superconducting transistor according to claim 1, wherein said superconducting collector layer (1) has a carrier concentration of 2x10²¹ to 2x10²²/cm³.
Claim 4
Dependent Claim
22 words
A superconducting transistor according claim 1 or 2, wherein said superconducting base layer (3) has a carrier concentration of 2x10²¹ to 2x10²²/cm³.
Claim 5
Dependent Claim
25 words
A superconducting transistor according to any one of the preceding claims, wherein said superconducting emitter layer (5) has a carrier concentration of 2x10²¹ to 2x10²²/cm³.
Claim 6
Dependent Claim
25 words
A superconducting transistor according to any one of the preceding claims, wherein said first barrier layer (2) has a carrier concentration of less than 2x10²¹/cm³.
Claim 7
Dependent Claim
25 words
A superconducting transistor according to any one of the preceding claims, wherein said second barrier layer (4) has a carrier concentration of less than 2x10²¹/cm³.
Claim 8
Dependent Claim
45 words
A superconducting transistor according to any one of the preceding claims, wherein said superconducting collector (1), base (3), and emitter (5) layers are (La 0.925 Sr 0.075 )₂CuO₄ and said first (2) and second (4) barrier layers are (La 1-x Sr x )₂CuO₄ where x<0.05.
Claim 9
Dependent Claim
43 words
A superconducting transistor according to any one of claims 1 to 6, wherein said superconducting collector (1), base (3) and emitter (5) layers are Ba₂YCu₃O 6.7 to 6.8 and said first (2) and second (4) barrier layers are Ba₂YCu₃O 6.0 to 6.4 .
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.