Title :
Nb/Al-AlOx/Nb overdamped junctions suitable for voltage standard operation above 4.2 K
Author :
Lacquaniti, Vincenzo ; Leo, Natascia De ; Fretto, Matteo ; Sosso, Andrea
Author_Institution :
Ist. Naz. di Ricerca Metrologica, Torino
Abstract :
Nb/Al-AlOx/Nb Josephson junctions of few micrometers size, derived by the basic hysteretic SIS process, have shown stable overdamped current voltage, I-V, characteristic with Ic of 1-10 mA and Vc of 100-600 muV at 4.2 K. The moderate dependence on temperature of these parameters has allowed to use them at temperatures above 4.2 K, near the Nb transition temperature, measuring quantized voltage steps several hundreds muA wide on single and 10 junctions arrays at T > 8 K. This paves the way to their use in cryocooler setup of reduced cost and power consumption for a future generation of programmable and AC voltage standard.
Keywords :
aluminium; measurement standards; niobium; superconducting arrays; superconducting junction devices; voltage measurement; AC voltage standard; Josephson junctions; Nb-Al-AlOx-Nb; cryocooler setup; current 1 mA to 10 mA; hysteretic SIS process; junctions arrays; overdamped current-voltage characteristics; overdamped junctions; temperature 4.2 K; voltage 100 muV to 600 muV; Current measurement; Hysteresis; Josephson junctions; Measurement standards; Niobium; Power measurement; Size measurement; Temperature dependence; Virtual colonoscopy; Voltage measurement;
Conference_Titel :
Precision Electromagnetic Measurements Digest, 2008. CPEM 2008. Conference on
Conference_Location :
Broomfield, CO
Print_ISBN :
978-1-4244-2399-6
Electronic_ISBN :
978-1-4244-2400-9
DOI :
10.1109/CPEM.2008.4574675
