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Chuang Liang, Fook L. Kim, Milja Medic, Prem Kumar, Robert Hadfield, Sae Woo Nam
We demonstrate the suitability of fiber-generated entangled photon pairs for practical quantum communications in the telecom band by measuring their properties with superconducting single-photon detectors that produce negligible dark counts. The photon
For the first time lumped series arrays of Josephson junctions have been fabricated with a transmission line-matched 50 Ohm nresistance and having the thousands of junctions necessary to produce a metrologically significant voltage. Using such arrays we
We have investigated arrays of bicrystal Josephson junctions for possible application in a quantized voltage noise source. In order to reduce the intrinsically high 100-150 GHz characteristic frequency of bicrystal junctions to the low 5 GHz drive
We present a detailed study of the electrical properties of planar Nb-MoSi2-Nb Josephson junctions. The Nb-MoSi2-Nb junction is an excellent system to study proximity-coupling in junctions with rigid superconductor/normal metal boundaries by controlling
Yonuk Chong, Charles J. Burroughs, Paul Dresselhaus, Nicolas Hadacek, Hirotake Yamamori, Samuel Benz
We have developed vertically stacked superconductor-normal metal- superconductor Josephson junction technology for the next generation quantum voltage standards. Stacked junctions provide a practical way of increasing the output voltage and operating
The unique ability of a Josephson junction to control the flow of magnetic flux quanta leads to a perfect relationship between frequency and voltage. Over the last 30 years, metrology laboratories have used this effect to greatly improve the accuracy of dc
Mayumi Ishizaki, Hirotake Yamamori, A. Shoji, Paul Dresselhaus, Samuel Benz
A programmable Josephson voltage standard chip using arrays of NbN/TiN/NbN/TiN/NbN double-junction stacks was fabricated and operated at 10 K. The circuit with over 260 000 junctions showed constant voltage steps at '}6V when driven with 11 GHz microwave
Yonuk Chong, Charles J. Burroughs, Paul D. Dresselhaus, Nicolas Hadacek, Hirotake Yamamori, Samuel P. Benz
We are developing MoSi2-barrier stacked junction arrays for Josephson voltage standards in order to increase the output voltage, operating bandwidth, and operating margins. In this paper we present results of a programmable voltage standard circuit with
Chris Conery, Loren F. Goodrich, Theodore C. Stauffer
The availability of very strong permanent magnets allows observation of phenomena previously difficult to see. The diamagnetism of water and diamagneticly stabilized magnetic levitation are now easy to demonstrate.
The superconducting analog of the single-electron transistor (SET), the single-Cooper-pair transistor (SCPT), is comprised of two ultrasmall tunnel junctions in series forming an island (see Figure 1(a)). Transport through the SCPT depends on the
Samuel Benz, Paul Dresselhaus, Yonuk Chong, Charles J. Burroughs
Superconducting Josephson voltage standard systems have replaced electrochemical cell (battery-like) artifact standards for voltage metrology because quantum-based systems produce precise and accurate voltages independent of any material parameters. The
This chapter reviews various methods commonly used for achieving the cryogenic temperatures required of superconducting materials. The problems associated with cryogenic refrigerators (cryocoolers), such as poor reliability, low efficiency, electromagnetic