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Search Publications by: Robert Schwall (Assoc)

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Displaying 1 - 25 of 29

Compact DC Josephson Voltage Standard

August 24, 2020
Author(s)
Alain Rufenacht, Anna E. Fox, Grace E. Butler, Charles J. Burroughs, Paul D. Dresselhaus, Robert E. Schwall, Stefan Cular, Samuel P. Benz
This paper presents precision measurements with a prototype cryogen-liquid-free DC Josephson voltage standard that produces a 1 V maximum output. Its cryostat is sufficiently compact that it can be operated on a bench close to devices under test. Compared

Development and Applications of a Four-Volt Josephson Arbitrary Waveform Synthesizer

February 13, 2020
Author(s)
Nathan E. Flowers-Jacobs, Alain Rufenacht, Anna E. Fox, Steven B. Waltman, Robert E. Schwall, Justus A. Brevik, Paul D. Dresselhaus, Samuel P. Benz
We have recently created a 4 V rms cryocooled JAWS (Josephson Arbitrary Waveform Synthesizer) using 204,960 nearly identical Josephson junctions (JJs) that are embedded in coplanar-wave guides. The JJs are pulse-biased at repetition rates up to 16 × 10 9

DC Comparison of a Programmable Josephson Voltage Standard and a Josephson Arbitrary Waveform Synthesizer

July 7, 2018
Author(s)
Alain Rufenacht, Nathan Flowers-Jacobs, Anna Fox, Steven B. Waltman, Robert E. Schwall, Paul Dresselhaus, Samuel P. Benz, Charles J. Burroughs
We present the first dc comparison of a programmable Josephson voltage standards and a pulse- driven Josephson arbitrary waveform synthesizer (JAWS) at 3 V. Both devices are mounted side- by-side on the cold stage of a cryocooler. The relative agreement

Automated Direct Comparison of Two Cryocooled 10 Volt Programmable Josephson Voltage Standards

July 6, 2018
Author(s)
Alain Rufenacht, Yi-hua D. Tang, Stephane Solve, Anna E. Fox, Paul D. Dresselhaus, Charles J. Burroughs, Robert E. Schwall, Regis Chayramy, Samuel P. Benz
We have performed direct dc comparisons between two cryocooled 10 V programmable Josephson voltage standards utilizing an automated synchronization scheme for the voltage reversals, which enables the use of a high-sensitivity analog null detector on its 10

10 Volt Automated Direct Comparison of Two Cryocooled Programmable Josephson Voltage Standards

July 9, 2016
Author(s)
Alain Rufenacht, Yi-hua D. Tang, Paul Dresselhaus, Charles J. Burroughs, Robert E. Schwall, Samuel P. Benz
We have performed direct dc comparisons between two cryocooled 10 V programmable Josephson voltage standards utilizing an automated synchronization scheme for the voltage reversals, which enables the use of a high sensitivity null detector on its 3 µV

Two Volt Josephson Arbitrary Waveform Synthesizer Using Wilkinson Dividers

February 19, 2016
Author(s)
Nathan E. Flowers-Jacobs, Anna E. Fox, Paul D. Dresselhaus, Robert E. Schwall, Samuel P. Benz
The root-mean-square (rms) output voltage of the NIST Josephson arbitrary waveform synthesizer (JAWS) has been doubled from 1 V to a record 2 V by combining two new 1 V chips on a cryocooler. This higher voltage will improve calibrations of ac thermal

Cryocooled 10 V Programmable Josephson Voltage Standard

December 11, 2014
Author(s)
Alain Rufenacht, Logan A. Howe, Anna E. Fox, Robert E. Schwall, Paul D. Dresselhaus, Charles J. Burroughs, Samuel P. Benz
Improvements in fabrication and packaging of our 10 V Programmable Josephson Voltage Standard circuits have enabled the successful operation of these devices on a cryocooler. Limited cooling power and temperature oscillations at the chip must not

Cryocooled 10 V Programmable Josephson Voltage Standard

December 11, 2014
Author(s)
Alain Rufenacht, Logan A. Howe, Anna Fox, Robert E. Schwall, Paul Dresselhaus, Charles J. Burroughs, Samuel Benz
Implementation of programmable Josephson voltage standard (PJVS) circuits on cryocooler at 4 K is a challenge. The limited cooling power of the cryocoolers has to balance the heat dissipated by the PJVS circuit in order to maintain a stable temperature

Performance Improvements for the NIST 1 V Josephson arbitrary waveform synthesizer

November 10, 2014
Author(s)
Samuel P. Benz, Steven B. Waltman, Anna E. Fox, Paul D. Dresselhaus, Alain Rufenacht, Logan A. Howe, Robert E. Schwall, Nathan E. Flowers-Jacobs
The performance of the NIST Josephson arbitrary waveform synthesizer has been improved such that it generates a root-mean-square (RMS) output voltage of 1 V with an operating current range greater than 2 mA. Our previous 1 V JAWS circuit achieved this same

NIST 10 V Programmable Josephson Voltage Standard System Using a Low Capacity Cryocooler

November 6, 2014
Author(s)
Logan A. Howe, Anna Fox, Alain Rufenacht, Charles J. Burroughs, Paul Dresselhaus, Samuel Benz, Robert E. Schwall
Rising costs of and difficulty in obtaining liquid helium in many areas of the world provides strong motivation for cryogen-free operation of superconducting devices such as NIST Programmable Josephson Voltage Standard (PJVS) systems. However, operation on

Standoff passive video imaging at 350 GHz with 251 superconducting detectors

June 20, 2014
Author(s)
Daniel T. Becker, James A. Beall, Hsiao-Mei Cho, Gene C. Hilton, Nicholas G. Paulter Jr., Carl D. Reintsema, Robert E. Schwall, Cale Gentry, Ilya Smirnov, Peter Ade, W D. Duncan, Mark Halpern, Carole Tucker
Millimeter wavelength radiation holds promise for detection of security threats at a distance, including suicide bomb belts and maritime threats in poor weather. The high sensitivity of superconducting Transition Edge Sensor (TES) detectors makes them

Cryogen-free Operation of 10 V Programmable Josephson Voltage Standards

June 1, 2013
Author(s)
Logan A. Howe, Charles J. Burroughs, Paul D. Dresselhaus, Samuel P. Benz, Robert E. Schwall
Given the recent shortages of liquid helium, cryogen-free operation of superconducting devices such as programmable Josephson voltage standard (PJVS) systems has become preferred worldwide, and a necessity in some locations. Besides consistent and accurate

A High Resolution High-Sensitivity Standoff Imaging System at 350 GHz

May 23, 2011
Author(s)
Daniel T. Becker, Cale Gentry, James A. Beall, Hsiao-Mei Cho, William Duncan, Gene C. Hilton, Kent D. Irwin, Peter J. Lowell, Michael D. Niemack, Nicholas G. Paulter Jr., Carl D. Reintsema, Francis J. Schima, Robert E. Schwall, Peter Ade, Carole Tucker, Simon Dicker, Halpern Mark
Millimeter wavelength radiation holds promise for detection of security threats at a distance, including suicide bomb belts and maritime threats in poor weather conditions. The sensitivity provided by superconducting Transition-Edge-Sensor (TES) bolometers

Practical Operation of Cryogen-free Programmable Josephson Voltage Standards

February 17, 2011
Author(s)
Robert E. Schwall, David Zilz, Jeffrey Power, Charles J. Burroughs, Paul D. Dresselhaus, Samuel P. Benz
Cryogen-free operation is rapidly becoming the preferred implementation of programmable Josephson voltage standard (PJVS) systems. There are strong operational incentives for using the smallest possible cryocooler in order to minimize acoustic noise

A 350-GHz high-resolution high-sensitivity passive video imaging system

April 27, 2010
Author(s)
Daniel T. Becker, James A. Beall, Hsiao-Mei Cho, William Duncan, Kent D. Irwin, Gene C. Hilton, Robert D. Horansky, Peter J. Lowell, Michael D. Niemack, Nicholas G. Paulter Jr., Carl D. Reintsema, Francis J. Schima, Robert E. Schwall, Ki W. Yoon, Peter Ade, Carole Tucker, Simon Dicker, Mark Halpern
We are developing a 350 GHz cryogenic passive video imaging system. This demonstration system uses 800 photon-noise-limited superconducting transition edge sensor bolometers. It will image a 1 m x 1 m area at a standoff distance of 16 m to a resolution of

Time-of-flight mass spectrometry with latching Nb meander detectors

June 1, 2009
Author(s)
Brian Estey, James A. Beall, Gene C. Hilton, Kent D. Irwin, Daniel R. Schmidt, Joel N. Ullom, Robert E. Schwall
Mass Spectrometry is widely used for protein characterization, structural virology, drug discovery, and clinical chemistry. However the detection efficiency of existing detectors for mass spectrometry degrades rapidly as mass is increased and is only ~10-5

Design of a Turn-Key 10 V Programmable Josephson Voltage Standard System

June 13, 2008
Author(s)
Paul D. Dresselhaus, Mike Elsbury, Charles J. Burroughs, David I. Olaya, Samuel P. Benz, Norman F. Bergren, Robert E. Schwall, Zoya Popovic
NIST is designing a 10 V Programmable Josephson Voltage Standard (PJVS) system with an improved microwave design and arrays of stacked NbXSi1-x-barrier Josephson junctions. For this new design a ?ground-up? approach, was used which takes into account all

An Optical System for Body Imaging from a Distance Using near-TeraHertz Frequencies

January 26, 2008
Author(s)
William Duncan, Robert E. Schwall, Kent D. Irwin, James A. Beall, Carl D. Reintsema, W.Bertrand (Randy) Doriese, Hsiao-Mei Cho, Brian Estey, Goutam Chattopadhyay, Peter Ade, Carole Tucker
We present the outline of the optical design of a TeraHertz (THz) imager for the detection of shrapnel-loaded improvised explosive devices (IED''s) at ''stand-off'' distances of 14 - 26 meters. The system will use 4 antenna-coupled TES detector arrays of

Quantum key distribution at 1550 nm with twin superconducting single-photon detectors

December 15, 2006
Author(s)
Robert Hadfield, Jonathan L. Habif, John Schlafer, Robert E. Schwall, Sae Woo Nam
The authors report on the full implementation of a superconducting detector technology in a fiber-based quantum key distribution (QKD) link. Nanowire-based superconducting single-photon detectors (SSPDs) offer single-photon detection with low dark counts

Quantum dot single photon sources studied with superconducting single photon detectors

November 1, 2006
Author(s)
Martin J. Stevens, Robert Hadfield, Robert E. Schwall, Sae Woo Nam, Richard P. Mirin
We report the observation of photon antibunching from a single, self-assembled InGaAs quantum dot (QD) at temperatures up to 135 K. The second-order intensity correlation, g(2)(0), is less than 0.260 ± 0.024 for temperatures up to 100 K. At 120 K, g(2)(0)

Single Photon Detector Comparison in a Quantum Key Distribution Link Testbed

October 25, 2006
Author(s)
Jonathan L. Habif, David S. Pearson, Robert Hadfield, Robert E. Schwall, Sae Woo Nam, Aaron J. Miller
We provide a direct comparison between the InGaAs avalanche photodiode (APD) and the NbN superconducting single photon detector (SSPD) for applications in fiber-based quantum cryptography. The quantum efficiency and dark count rate were measured for each

Time-correlated single-photon counting with superconducting single-photon detectors

October 1, 2006
Author(s)
Martin Stevens, Robert Hadfield, Robert E. Schwall, Sae Woo Nam, Richard Mirin
We report use of a niobium nitride superconducting single-photon detector in a time-correlated single-photon counting experiment. The detector has a timing jitter of 68 +/- 3 ps full-width at half-maximum with a Gaussian temporal profile. The detector's

Single photon source characterization with a superconducting single photon detector

December 26, 2005
Author(s)
Robert Hadfield, Martin Stevens, Stephen Gruber, Aaron J. Miller, Robert E. Schwall, Richard Mirin, Sae Woo Nam
Superconducting single photon detectors (SSPD) based on nanopatterned niobium nitride wires offer single photon counting at fast rates, low jitter, and low dark counts, from visible wavelengths well into the infrared. We demonstrate the first use of an