Ultra-short weak links of superconductors
Nanometer long weak links of quasi-planar geometrical structure have been made only of niobium. The critical current of an two-junction interferometer of the nanometer-long quasi-planar Josephson junctions (QPJJ) has been changed by a magnetic field to be one quarter of the zero-field critical current. This is important for applications of weak links to both DC SQUID and logic circuits. Microwave response of QPJJ's were excellent at 10,24, and 110 GHz. Change in the critical current of 10 ..mu..A was less than 10 % after 50 times temperature cycles between liquid helium temperature and room temperature. QPJJ's are very reproducibaly fabricated by lithographic techniques even though surface of niobium thin films is very active chemically. It would be safe now to say that we have obtained a mechanically stable substitute for a point contact Josephson junction of niobium. New fluxoid-type logic circuits have been proposed which can be made of weak links rather than Josephson tunnel junctions.
- Research Organization:
- The Institute of Physical and Chemical Research, Wako-shi, Saitama
- OSTI ID:
- 6485638
- Report Number(s):
- CONF-840937-
- Journal Information:
- IEEE Trans. Magn.; (United States), Vol. MAG-21:2; Conference: Applied superconductivity conference, San Diego, CA, USA, 9 Sep 1984
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
JOSEPHSON JUNCTIONS
CRITICAL CURRENT
SUPERCONDUCTORS
FABRICATION
GHZ RANGE 100-1000
INTERFEROMETERS
LOGIC CIRCUITS
NIOBIUM
SQUID DEVICES
TEMPERATURE DEPENDENCE
THIN FILMS
CURRENTS
ELECTRIC CURRENTS
ELECTRONIC CIRCUITS
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
FILMS
FLUXMETERS
FREQUENCY RANGE
GHZ RANGE
JUNCTIONS
MEASURING INSTRUMENTS
METALS
MICROWAVE EQUIPMENT
SUPERCONDUCTING DEVICES
SUPERCONDUCTING JUNCTIONS
TRANSITION ELEMENTS
420201* - Engineering- Cryogenic Equipment & Devices