Electronic Resource
Woodbury, NY
:
American Institute of Physics (AIP)
Applied Physics Letters
57 (1990), S. 2487-2489
ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
We have made accurate measurements of the noise and gain of heterodyne mixers employing small-area (1 μm2) Ta/Ta2O5/Pb0.9Bi0.1 superconductor-insulator-superconductor tunnel junctions. These junctions have very low subgap leakage current and an extremely sharp current rise at the sum gap. We have measured an added mixer noise of 0.61±0.31 quanta at 95.0 GHz, which is within 25% of the quantum limit of 0.5 quanta for a single-sideband mixer. Values of the imbedding admittances are deduced from the shapes of I-V curves pumped at the upper and lower sideband frequencies. Using these admittances, the mixer performance calculated from the quantum theory is in good agreement with the experiment.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.104111
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