Claims
- 1. A method of fabricating a grain boundary Josephson junction on a substrate, the method comprising:
forming a superconducting layer on the substrate; patterning the superconducting layer thereby forming said grain boundary Josephson junction on said substrate; and annealing said grain boundary Josephson junction on said substrate.
- 2. The method of claim 1, wherein said annealing comprises exposing said grain boundary Josephson junction on said substrate to an O2 plasma.
- 3. The method of claim 2, wherein said pressure of said O2 plasma during at least a portion of said exposing is about 0.2 mbar to about 0.6 mbar.
- 4. The method of claim 2, wherein said grain boundary Josephson junction on said substrate is exposed to said O2 plasma for at least fifteen minutes.
- 5. The method of claim 1, the method further comprising heating said grain boundary Josephson junction on said substrate to a temperature of about 80° C. to about 120° C.
- 6. The method of claim 1, wherein the substrate is a bi-crystal substrate.
- 7. The method of claim 1 wherein the grain boundary Josephson junction has a width that is smaller than a width of a facet in said substrate.
- 8. The method of claim 7 wherein the grain boundary Josephson junction has a width between about 10 nm and about 100 nm.
- 9. The method of claim 1 wherein, forming the superconducting layer on the substrate comprises:
depositing a first superconducting material over a first portion of the substrate; and depositing a second superconducting material over a second portion of the substrate, wherein said depositing said first superconducting material and said depositing said second superconducting material occurs at the same time.
- 10. The method of claim 9 wherein
said first portion of the substrate has a first crystallographic orientation and said first superconducting material adopts said first crystallographic orientation; and said second portion of the substrate has a second crystallographic orientation that is different than said first crystallographic orientation and said second superconducting material adopts said second crystallographic orientation.
- 11. The method of claim 1, wherein the superconducting layer comprises an unconventional superconducting material.
- 12. The method of claim 11 wherein the superconducting material layer is a d-wave material.
- 13. The method of claim 12 wherein the superconducting material is YBa2CuOx.
- 14. The method of claim 1 wherein said patterning further comprises:
forming a space between a first portion of the superconducting layer and a second portion of the superconducting layer; and depositing a material in the space, wherein said material is not an unconventional superconductor.
- 15. The method of claim 14 wherein said material is selected from the group consisting of a non-superconducting metal, a semiconductor, and a dielectric material.
- 16. The method of claim 1 wherein the substrate is a single crystal substrate having a crystallographic orientation, the method further comprising:
depositing a seed layer on a first portion of the substrate prior to forming the superconducting layer, wherein the seed layer has a crystallographic orientation that differs from the crystallographic orientation of the substrate.
- 17. The method of claim 1 wherein the superconducting layer is a d-wave superconductor, the method further comprising:
forming an s-wave superconductor layer on the substrate; and depositing a normal material between the d-wave superconductor and the s-wave superconductor.
- 18. The method of claim 1 wherein said annealing comprises contacting the grain boundary Josephson junction on said substrate with an O2 and N2 gas mixture.
- 19. The method of claim 18, wherein said O2 and N2 gas mixture is formed from a gas mixture that comprises about 500 mbar N2 to about 1100 mbar N2 and about 100 mbar O2 to about 400 mbar O2.
- 20. The method of claim 18, wherein said O2 and N2 gas mixture is formed from a gas mixture that comprises about 800 mbar of N2 and about 200 mbar of O2.
- 21. The method of claim 18, the method further comprising heating the grain boundary Josephson junction on said substrate to a temperature of about 160° C. to about 240° C.
- 22. An apparatus including a grain boundary Josephson junction, wherein the grain boundary Josephson junction is manufactured by the method comprising:
forming a superconducting layer on a substrate; patterning the superconducting layer thereby forming said grain boundary Josephson junction on said substrate; and annealing said grain boundary Josephson junction on said substrate.
- 23. The apparatus of claim 22, wherein said annealing comprises exposing said grain boundary Josephson junction on said substrate to an O2 plasma.
- 24. The apparatus of claim 23, wherein said pressure of said O2 plasma during at least a portion of said exposing is about 0.2 mbar to about 0.6 mbar.
- 25. The apparatus of claim 23, wherein said grain boundary Josephson junction on said substrate is exposed to said O2 plasma for at least fifteen minutes.
- 26. The apparatus of claim 22, wherein the substrate is a bi-crystal substrate.
- 27. The apparatus of claim 22 wherein the grain boundary Josephson junction has a width that is smaller than a width of a facet in said substrate.
- 28. The apparatus of claim 22 wherein the grain boundary Josephson junction has a width between about 10 nm and about 100 nm.
- 29. The apparatus of claim 22 wherein, forming a superconducting layer on the substrate comprises:
depositing a first superconducting material over a first portion of the substrate; and depositing a second superconducting material over a second portion of the substrate, wherein said depositing said first superconducting material and said depositing said second superconducting material occurs at the same time.
- 30. The apparatus of claim 29 wherein said first portion of the substrate has a first crystallographic orientation and said first superconducting material adopts said first crystallographic orientation; and
said second portion of the substrate has a second crystallographic orientation that is different than said first crystallographic orientation and said second superconducting material adopts said second crystallographic orientation.
- 31. The apparatus of claim 22, wherein the superconducting layer comprises an unconventional superconducting material.
- 32. The apparatus of claim 31 wherein the superconducting material is a d-wave material.
- 33. The apparatus of claim 32 wherein the superconducting material is YBa2CuOx.
- 34. The apparatus of claim 22 wherein said patterning further comprises:
forming a space between a first portion of the superconducting layer and a second portion of the superconducting layer; and depositing a material in the space, wherein said material is not an unconventional superconductor.
- 35. The apparatus of claim 34 wherein said material is selected from the group consisting of a non-superconducting metal, a semiconductor, and a dielectric material.
- 36. The apparatus of claim 22 wherein the substrate is a single crystal substrate having a crystallographic orientation, the method further comprising:
depositing a seed layer on a first portion of the substrate prior to forming the superconducting layer, wherein the seed layer has a crystallographic orientation that differs from the crystallographic orientation of the substrate.
- 37. The apparatus of claim 22 wherein said annealing comprises contacting the grain boundary Josephson junction on said substrate with an O2 and N2 gas mixture
- 38. The apparatus of claim 37, wherein said O2 and N2 plasma mixture is formed from a gas mixture that comprises about 500 mbar N2 to about 1100 mbar N2 and about 100 mbar O2 to about 400 mbar O2.
- 39. The apparatus of claim 37, wherein said apparatus is selected from the group consisting of a superconducting quantum interference device, a radiation detector, a spectrometer, a three-terminal device, and a superconducting logic circuit.
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Patent Application No. 60/316,378, “Oxygen Doping of Grain Boundary Josephson Junctions,” filed on Aug. 30, 2001. U.S. Provisional Patent Application No. 60/316,378 is incorporated herein in its entirety by this reference.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60316378 |
Aug 2001 |
US |