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Search Publications by: Paul Dresselhaus (Fed)

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Displaying 26 - 50 of 170

1 GHz Waveform Synthesis With Josephson Junction Arrays

July 31, 2019
Author(s)
Christine A. Donnelly, Nathan E. Flowers-Jacobs, Justus A. Brevik, Anna E. Fox, Paul D. Dresselhaus, Peter F. Hopkins, Samuel P. Benz
We synthesize single- and multiple-tone waveforms at gigahertz frequencies from arrays of Josephson junctions and demonstrate their quantum-locked operation over a range of experimental input parameters. We first use a lumped-element circuit to synthesize

Quantized Pulse Propagation in Josephson Junction Arrays

July 23, 2019
Author(s)
Christine A. Donnelly, Justus Brevik, Nathan Flowers-Jacobs, Anna Fox, Paul Dresselhaus, Peter F. Hopkins, Samuel Benz
We present time-domain electrical measurements and simulations of the quantized voltage pulses that are generated from series-connected Josephson junction (JJ) arrays. The transmission delay of the JJ array can lead to a broadening of the net output pulse

Induced Current Effects in Josephson Voltage Standard Circuits

March 8, 2019
Author(s)
Anna E. Fox, Grace E. Butler, Miranda L. Thompson, Paul D. Dresselhaus, Samuel P. Benz
A study has been performed to understand the effects of magnetic field induced current in Josephson voltage standard circuits. Inductive filtering is an essential component in Josephson voltage standard devices for isolation of the microwave and DC bias

Planarized process for single-flux-quantum circuits with self-shunted Nb/NbxSi1-x/Nb Josephson junctions

February 18, 2019
Author(s)
David I. Olaya, Manuel C. Castellanos Beltran, Javier Pulecio, John P. Biesecker, Soroush Khadem, Theodore Lewitt, Peter F. Hopkins, Paul D. Dresselhaus, Samuel P. Benz
We describe the single-flux-quantum (SFQ) circuit fabrication process employed at NIST's Boulder Microfabrication Facility. The process includes four superconducting metal layers, one palladium-gold resistor layer, and a contact pad layer. Chemical

RF waveform synthesizers with quantum-based voltage accuracy for communications metrology

February 11, 2019
Author(s)
Peter F. Hopkins, Justus A. Brevik, Manuel C. Castellanos Beltran, Nathan E. Flowers-Jacobs, Anna E. Fox, David I. Olaya, Christine A. Donnelly, Paul D. Dresselhaus, Samuel P. Benz
We report on NIST’s development of Josephson junction-based programmable reference sources to synthesize quantum-accurate, spectrally-pure waveforms for characterizing and improving next generation communication devices and systems. The goal is to provide

Stacked Josephson Junctions as inductors for SFQ circuits

February 11, 2019
Author(s)
Manuel C. Castellanos Beltran, David I. Olaya, Adam J. Sirois, Paul D. Dresselhaus, Samuel P. Benz, Peter F. Hopkins
In order for Single Flux Quantum (SFQ) circuits to be scaled to densities needed for large-scale integration, typical lithographically-patterned circuit components should be made to be as compact as possible. In this work, we characterize the performance

Jitter Sensitivity Analysis for Pulsed-Output RF Superconducting Digital to Analog Converters

November 5, 2018
Author(s)
Christine A. Donnelly, Justus A. Brevik, Paul D. Dresselhaus, Peter F. Hopkins, Samuel P. Benz
We present the first analysis of the jitter sensitivity of a superconductive digital-to-analog converter (DAC)for use as a reference RF source. This analysis is important for maintaining quantum-accurate voltage output as we extend our superconductor-based

Characterization of a Dual Josephson Impedance Bridge

October 21, 2018
Author(s)
Nathan Flowers-Jacobs, Blaise Jeanneret, Frederic Overney, Alain Rufenacht, Anna Fox, Paul Dresselhaus, Samuel P. Benz
This paper describes a dual Josephson impedance bridge capable of comparing any two impedances, that is, with any amplitude ratio and relative phase, over a wide range of frequency. A new, more compact, design has been achieved by mounting the two

Measurement of Leakage Current to Ground in Programmable Josephson Voltage Standard

July 8, 2018
Author(s)
Alain Rufenacht, Charles J. Burroughs, Paul D. Dresselhaus, Samuel P. Benz
The voltage error associated with the leakage current of programmable Josephson voltage standards (PJVS) is one of the largest contributions to the uncertainty in direct comparison of voltage standards. Due to the parallel biasing scheme of the PJVS and

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

Measuring the Leakage Current to Ground in Programmable Josephson Voltage Standards

July 7, 2018
Author(s)
Alain Rufenacht, Charles J. Burroughs, Paul Dresselhaus, Samuel P. Benz
The voltage error associated with the leakage current of programmable Josephson voltage standards (PJVS) is one of the largest contributions to the uncertainty in direct comparison of voltage standards. Due to the parallel biasing scheme of the PJVS and

Radiofrequency Waveform Synthesis with the Josephson Arbitrary Waveform Synthesizer

July 7, 2018
Author(s)
Justus Brevik, Christine A. Donnelly, Nathan Flowers-Jacobs, Anna Fox, Pete Hopkins, Paul Dresselhaus, Samuel P. Benz
We have measured the frequency-dependent voltage output up to 100 MHz of a modified version of the Josephson Arbitrary Waveform Synthesizer. An impedance-matching resistor was integrated within the Josephson junction array circuit to match the nominally

Three Volt Pulse-Driven Josephson Arbitrary Waveform Synthesizer

July 7, 2018
Author(s)
Nathan Flowers-Jacobs, Alain Rufenacht, Anna Fox, Steven B. Waltman, Justus Brevik, Paul Dresselhaus, Samuel P. Benz
This paper describes a new generation of Josephson Arbitrary Waveform Synthesizers which generate ac waveforms with a root-mean-squared (rms) amplitude of 3 V over a quantum-accurate operating range greater than 1 mA at 1 kHz. This system is composed of

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

Ultralow power artificial synapses using nanotextured magnetic Josephson junctions

January 28, 2018
Author(s)
Michael L. Schneider, Christine A. Donnelly, Stephen E. Russek, Burm Baek, Matthew R. Pufall, Peter F. Hopkins, Paul D. Dresselhaus, Samuel P. Benz, William H. Rippard
Neuromorphic computing is a promising avenue to dramatically improve the efficiency of certain computational tasks, such as perception and decision making. Neuromorphic systems are currently being developed for critical applications ranging from self

Fabrication of High-Speed and High-Density Single-Flux-Quantum Circuits at NIST

June 11, 2017
Author(s)
David Olaya, Paul Dresselhaus, Pete Hopkins, Samuel P. Benz
The development of a fabrication process for single-flux-quantum (SFQ) digital circuits is a fundamental part of the NIST effort to develop a gigahertz waveform synthesizer with quantum voltage accuracy. This paper describes the current SFQ fabrication

Scalable, High-Speed, Digital Single-Flux-Quantum Circuits at NIST

June 11, 2017
Author(s)
Pete Hopkins, Manuel Castellanos Beltran, Christine A. Donnelly, Paul Dresselhaus, David Olaya, Adam Sirois, Samuel P. Benz
We describe NIST's capabilities for designing and fabricating niobium-based single-flux quantum (SFQ) digital and mixed-signal circuits and show test results of our first circuits. We have assembled a package of software design tools that are readily

Advanced Waveform Synthesis with Pulse-driven Josephson Voltage Standards

February 21, 2017
Author(s)
Justus A. Brevik, Nathan E. Flowers-Jacobs, Anna E. Fox, Evan B. Golden, Paul D. Dresselhaus, Samuel P. Benz
We describe the implementation of new commercial pulse-bias electronics that have enabled an improvement in the generation of quantum-accurate waveforms both with and without low-frequency compensation biases. We have used these electronics to apply a

On-Chip Temperature Distribution for Josephson Voltage Standards

November 22, 2016
Author(s)
Anna E. Fox, Evan B. Golden, Paul D. Dresselhaus, Samuel P. Benz
A substrate surface temperature characterization for the National Institute of Standards and technology Josephson voltage standard has been performed by fabricating and measuring Josephson junction arrays with on-chip thermometry. Circuits were designed

Stochastic Single Flux Quantum Neuromorphic Computing using Magnetically Tunable Josephson Junctions

October 16, 2016
Author(s)
Stephen E. Russek, Christine A. Donnelly, Michael Schneider, Burm Baek, Matthew Pufall, William Rippard, Pete Hopkins, Paul Dresselhaus, Samuel P. Benz
Abstract— Single flux quantum (SFQ) circuits form a natural neuromorphic technology with SFQ pulses and superconducting transmission lines simulating action potentials and axons, respectively. Here we present a new component, magnetic Josephson junctions

2 V Pulse-Driven Josephson Arbitrary Waveform Synthesizer

July 10, 2016
Author(s)
Nathan E. Flowers-Jacobs, Alain Rufenacht, Anna E. Fox, Paul D. Dresselhaus, Samuel P. Benz
We created a Josephson Arbitrary Waveform Synthesizer (JAWS) with a root-mean-square (rms) output magnitude of 2 V. This system is composed of two 1 V chips operating on a cryocooler. By controlling the relative phase of the two chips’ output voltage, we

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

Direct comparison of a Pulse-driven Josephson Arbitrary Waveform Synthesizer and a Programmable Josephson Voltage Standard at 1 Volt

July 9, 2016
Author(s)
Alain Rufenacht, Nathan Flowers-Jacobs, Anna Fox, Charles J. Burroughs, Paul Dresselhaus, Samuel P. Benz
We have performed direct ac comparisons between two types of quantum voltage standards, a pulse- driven Josephson arbitrary waveform synthesizer and a programmable Josephson voltage standard, at 1 V rms amplitude and a frequency of 100 Hz. The system

Simultaneous Double Waveform Synthesis with a Single Programmable Josephson Voltage Standard

July 9, 2016
Author(s)
Alain Rufenacht, Anna Fox, Paul Dresselhaus, Charles J. Burroughs, Samuel P. Benz, Bryan C. Waltrip, Thomas L. Nelson
We have recently demonstrated new 2 V PJVS devices configured with two voltage outputs and two sets of least significant bits in order to simultaneously generate two independent stepwise output waveforms. This development improves upon our previous