Terahertz transistor

Patent metadata

Field	Value
Publication number	US-12290009-B2
Application number	US-202016860839-A
Country	US
Kind code	B2
Filing date	Apr 28, 2020
Priority date	May 20, 2016
Publication date	Apr 29, 2025
Grant date	Apr 29, 2025

Abstract

Superconducting Meissner effect transistors, methods of modulating, and systems are disclosed. In one aspect a disclosed transistor includes a superconducting bridge between a first and a second current probe, the first and second current probe being electrically connected to a source and a drain electrical connection, respectively and a control line configured to emit a magnetic field signal having signal strength H sig at the superconducting bridge. In one aspect the emitted magnetic field is configured to break Cooper pairs in the superconducting bridge.

First claim

The invention claimed is:

1. A superconducting Meissner effect transistor comprising:
a superconducting bridge between a first and a second current probe, wherein the superconducting bridge is continuous between the first and second current probe without a Josephson junction, the first and second current probe being electrically connected to a source and a drain electrical connection and having a superconducting current between the source and drain electrical connection, respectively, and wherein the superconducting bridge is adapted to include a plurality of Cooper pairs;
a magnet, external to the superconducting bridge, emitting a magnetic field bias having a bias strength (H a ) at the superconducting bridge,
wherein, each Cooper pair includes a pair of electrons having anti-parallel spins when the superconducting bridge is subjected to the bias strength (H a ); and
a control line having a time varying magnetic field signal emitted therefrom, the magnetic field signal having a signal strength H sig at the superconducting bridge sufficient, in combination with the bias strength H a , to align each of the spins of the electrons in at least a portion of the Cooper pairs such that the portion of the Cooper pairs are broken,
wherein the magnetic field signal has a signal frequency less than the inverse of a relaxation time τ 0 of the superconducting bridge and the superconducting current is modulated at the signal frequency.

2. The transistor of claim 1 , wherein the superconducting bridge is adapted such that breaking Cooper pairs in the superconducting bridge decreases conductivity of the superconducting bridge.

3. The transistor of claim 1 , wherein the superconducting bridge is adapted to include the plurality of Cooper pairs having anti-parallel spins when the combination of H sig and H a ) is less than or equal to a critical field value (H c ) for the superconducting bridge.

4. The transistor of claim 3 , wherein H a is less than or equal to the magnitude of H sig subtracted from H c .

5. The transistor of claim 3 , wherein H sig has a maximum strength of H sig-max and a minimum strength of H sig-min .

6. The transistor of claim 5 , herein H a is less than or equal to the magnitude of H sig-max subtracted from H c .

7. The transistor of claim 3 , wherein the superconducting bridge is a type I superconductor.

8. The transistor of claim 3 , wherein the superconducting bridge is a type II superconductor and H c is equal to H c1 and H c1 is a strength of the magnetic field at the superconducting bridge at an onset of a mixed state of superconductivity for the superconducting bridge.

9. The transistor of claim 1 , wherein the superconducting bridge has a temperature that is less than or equal to its critical temperature (T c ).

10. The transistor of claim 1 , wherein the superconducting bridge comprises niobium and/or niobium alloys.

11. The transistor of claim 10 , wherein the superconducting bridge has a temperature that is less than or equal to its critical temperature (T c ) and greater than or equal to about 0.2K.

12. The transistor of claim 9 , wherein the superconducting bridge has a temperature that is less than or equal to its critical temperature (T c ) and greater than or equal to about 2.2K.

13. The transistor of claim 9 , wherein the superconducting bridge has a temperature that is less than or equal to its critical temperature (T c ) and greater than or equal to about 3K.

14. The transistor of claim 1 having a frequency response about equal to the recombination of Cooper pairs for the superconducting bridge material being utilized.

15. The transistor of claim 10 , wherein the frequency response is between about 0.7 THz and about 1.25 THz.

16. A first transistor of claim 1 and a second transistor of claim 1 , wherein the first transistor is configured to emit a photon in the presence of the magnetic field bias and the magnetic field signal, and the second transistor is configured to vary its conductivity based on the emitted photon.

17. The transistor of claim 4 , wherein the magnitude of H a and H sig , combined, is equal to H c and the superconductor bridge is normal.

18. The transistor of claim 10 , wherein the niobium and/or niobium alloys is continuous between the first and second current probes.

19. The transistor of claim 1 , wherein the spins of each of the electrons in the at least a portion of the Cooper pairs are aligned according to the Meissner effect.

20. The transistor of claim 1 , wherein the signal strength H sig at the superconducting bridge is sufficient, in combination with the magnetic field bias strength H a , to align each of the spins of the electrons in fewer than all of the Cooper Pairs.

21. The transistor of claim 1 , wherein the magnetic field signal has a frequency less than a gap frequency Vg of an energy gap E g of the superconducting bridge.

22. The transistor of claim 5 , herein H a is equal to the magnitude of H sig subtracted from H c .

Assignees

• Arizona Board Of Regents On Behalf Of Univ Of Arizona
• Univ Arizona

Inventors

• Walker Christopher K

Classifications

• H10N60/208

  based on Abrikosov vortices · CPC title

• H10N60/85

  Superconducting active materials · CPC title

• H10N60/35

  Cryotrons · CPC title

• H03B15/003

  using superconductivity effects (devices using superconductivity H10N60/00) · CPC title

• H03K19/20

  characterised by logic function, e.g. AND, OR, NOR, NOT circuits (H03K19/003 - H03K19/01 take precedence) · CPC title