Quantum-limited heterodyne detection of millimeter waves using superconducting tantalum tunnel junctions

Journal Article · Sun Dec 02 23:00:00 EST 1990 · Applied Physics Letters; (USA)

DOI:https://doi.org/10.1063/1.104111· OSTI ID:6008562

Mears, C A; Hu, Q; Richards, P L ^[1]; Worsham, A H; Prober, D E ^[2]; Raeisaenen, A V ^[3]

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1. Department of Physics, University of California at Berkeley, Berkeley, CA (USA) Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, CA (USA)
2. Department of Applied Physics, Yale University, New Haven, CT (USA)
3. Radio Laboratory, Helsinki University of Technology, Espoo (Finland)

We have made accurate measurements of the noise and gain of heterodyne mixers employing small-area (1 {mu}m{sup 2}) Ta/Ta{sub 2}O{sub 5}/Pb{sub 0.9}Bi{sub 0.1} 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{plus minus}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 {ital I}-{ital 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.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6008562
• Journal Information: Applied Physics Letters; (USA), Journal Name: Applied Physics Letters; (USA) Vol. 57:23; ISSN APPLA; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

426001* -- Engineering-- Superconducting Devices & Circuits-- (1990-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
AMPLIFICATION
BISMUTH ALLOYS
CHALCOGENIDES
CURRENTS
DATA
DETECTION
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
EXPERIMENTAL DATA
GAIN
HETERODYNE RECEIVERS
INFORMATION
JUNCTION DETECTORS
JUNCTIONS
LEAD ALLOYS
LEAD BASE ALLOYS
LEAKAGE CURRENT
MEASURING INSTRUMENTS
METALS
MICROWAVE EQUIPMENT
MICROWAVE RADIATION
MIXERS
NOISE
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
PHYSICAL PROPERTIES
RADIATION DETECTION
RADIATION DETECTORS
RADIATIONS
RADIO EQUIPMENT
REFRACTORY METAL COMPOUNDS
SEMICONDUCTOR DETECTORS
SUPERCONDUCTING JUNCTIONS
TANTALUM
TANTALUM COMPOUNDS
TANTALUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
USES