Ultra high-frequency superconductive devices. Final report, Oct 86-Mar 90

Technical Report · Wed May 01 04:00:00 EDT 1991

OSTI ID:5234276

Buhrman, R A

The objective of this research program was to develop advanced superconducting tunnel junctions for application in superconducting local oscillators and superconducting mixers operating in the Terahertz (0.2 - 2.0 THz) frequency regime. The research was focused on the development of stable, all refractory, high-critical-current-density, small-area tunnel junctions based on NbN superconducting thin films. A successful process for fabrication of approx. 1 sq. micrometer NbN-MgO-NbN Josephson tunnel junctions was developed with the junctions having critical current densities equal to or greater than 10.000 A/sq. cm. Such junctions were found to be very rugged and reliable. In experiments in which such junctions were coupled capacitively to a nearby, on-chip, Josephson junction detector, the NbN junctions were found to be effective voltage-tunable oscillators from 300 GHz to above 1.4 Thz. Direct measurement of the response of the detector junction indicated that the oscillator voltage was typically 1.5 mV in amplitude. This indicated that the Terahertz oscillator power was of the order of 0.5 uW, of which, due to impedance mismatch, 0.01 micro W was typically coupled into the detector junction. This power is quite adequate for local oscillator applications in Terahertz mixer applications that might employ a superconducting SIS detector.

• Research Organization: Cornell Univ., Ithaca, NY (United States). School of Applied and Engineering Physics
• OSTI ID: 5234276
• Report Number(s): AD-A-236795/1/XAB; CNN: F19628-86-K-0034
• Country of Publication: United States
• Language: English

Related Subjects

426001* -- Engineering-- Superconducting Devices & Circuits-- (1990-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
CRITICAL CURRENT
CURRENT DENSITY
CURRENTS
ELECTRIC CURRENTS
ELECTRONIC EQUIPMENT
EQUIPMENT
FABRICATION
FILMS
FUNCTIONS
JOSEPHSON JUNCTIONS
JUNCTIONS
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
NIOBIUM COMPOUNDS
NIOBIUM NITRIDES
NITRIDES
NITROGEN COMPOUNDS
OSCILLATORS
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
REFRACTORY METAL COMPOUNDS
RESEARCH PROGRAMS
RESPONSE FUNCTIONS
SUPERCONDUCTING DEVICES
SUPERCONDUCTING FILMS
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTORS
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
TUNNEL EFFECT
USES