Experimental evidence of Josephson noise in superconductor-insulator-superconductor quasiparticle mixers

Journal Article · Mon Sep 01 04:00:00 EDT 1997 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.366160· OSTI ID:542162

Leridon, B; Febvre, P; George, S ^[1]; Feautrier, P ^[2]; McGrath, W R ^[3]

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1. DEMIRM, Observatoire de Paris-61, avenue de lObservatoire-75014 Paris (France)
2. Observatoire de Grenoble-BP53X-414, rue de la Piscine-38041 Grenoble Cedex (France)
3. JPL, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)

Josephson currents have been observed to drain instabilities and decrease the sensitivity of a heterodyne superconductor-insulator-superconductor (SIS) receiver operated at submillimeter wavelengths. A static magnetic field is usually applied on the SIS junction to reduce the magnitude of its critical Josephson currents and enable quasiparticle mixing. We measured the SIS mixer output power at the intermediate frequency (IF) versus the dc bias voltage of an array of two 1 {mu}m{sup 2} Nb/Al{endash}Al{sub 2}O{sub 3}/Nb junctions. We show evidence of additional, magnetic-field-sensitive noise, peaked at the Shapiro steps voltages, which is due to high-frequency Josephson currents converted to the IF by quasiparticle mixing. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 542162
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 82; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ALUMINIUM
ALUMINIUM OXIDES
HETERODYNE RECEIVERS
INSTABILITY
JOSEPHSON EFFECT
MIXERS
NIOBIUM
NOISE
SUPERCONDUCTING DEVICES