In-situ tunable Josephson weak links

US5432149A · kind A · utility

Assignee

• The Regents of the University of California · US

Inventors

• Ivan K. Schuller · San Diego, US
• Gladys L. Nieva · Municipio de Leandro N. Alem, AR
• Julio J. Guimpel · Municipio de Leandro N. Alem, AR
• Eduardo Osquiguil · Kessel-Lo, BE
• Yvan Bruynseraede · Linden, BE

Key dates

• Filing date: Apr 8, 1994
• Grant date: Jul 11, 1995
• Expiry date: Apr 8, 2014

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S505/702

Abstract

A weak link is patterned from a high-temperature superconducting film using standard lithographic techniques. Once the area in which the weak link is to be located is defined, the remainder of the film is covered with an oxygen-impermeable material. The oxygen is then removed in the weak link area by placing the sample in a vacuum furnace at a sufficient temperature to drive out the oxygen. Once the oxygen is removed, the weak link becomes non-superconducting. A high power solid state laser is placed in front of the weak link, and superconductivity is restored in the weak link area, in situ. The process is performed in a liquid nitrogen environment.