Interaction of electromagnetic radiation with Josephson microbridges in a resonant structure

Thesis/Dissertation · Wed Dec 31 23:00:00 EST 1980

OSTI ID:6770093

Stern, M B

In this thesis, the results of an experimental investigation of the resonant interaction between indium microbridges and a continuously tunable X-band resonant structure are reported. Josephson microbridges, fabricated by an electron beam lithography technique, are mounted parallel to the vector E field direction of the dominant TE/sub 10/ mode. The effects that varying the coupling between the junction-resonator system and the external load, or the loaded Q/sub L/ of the cavity, has on the radiation spectrum and on the IVC are examined. Increasing Q/sub L/ results in a larger cavity-induced step structure in the IVC at the resonant voltage and decreased dynamic resistance, R/sub D/, along the step. Josephson radiation has been investigated as a function of Q/sub L/ and temperature, T, at 9.1 GHz. The radiation linewidth, ..delta.. nu, and the total radiation power, P, vary with the output coupling, controlled by a tunable iris in the resonant structure. For high Q values, ..delta.. nu is two to three orders of magnitude less than the resonator bandwidth and is related to the rapid decrease in R/sub D/ with increasing Q/sub L/. P is maximum when the junction is critically coupled to the external load for T approx. T/sub c/. As T is decreased, P increases and ..delta.. nu decreases, saturating at low T. The peak power decreases and ..delta.. nu increases as the bias current is increased along the step, with maximum power and minimum linewidth occurring at frequency ..omega.. approx. ..omega../sub R/.

• Research Organization: State Univ. of New York, Stony Brook (USA)
• OSTI ID: 6770093
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CAVITY RESONATORS
DATA
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
EXPERIMENTAL DATA
INDIUM
INFORMATION
INTERACTIONS
JOSEPHSON JUNCTIONS
JUNCTIONS
METALS
NUMERICAL DATA
RADIATIONS
RESONANCE
RESONATORS
SUPERCONDUCTING JUNCTIONS
TEMPERATURE DEPENDENCE