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Search Publications by: Samuel P. Benz (Fed)

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Displaying 76 - 100 of 277

Nanoscale Spin Valve Josephson Junction Devices

April 14, 2015
Author(s)
Burm Baek, William H. Rippard, Matthew R. Pufall, Samuel P. Benz, Stephen E. Russek, Horst Rogalla, Paul D. Dresselhaus
Traditionally, superconductivity and magnetism have had a mutually exclusive relationship. However, the physics of superconductor-ferromagnet hybrid structures turned out to be far from being simply destructive, which has led to the hope of a new breed of

Spin-transfer torque switching observed in nanopillar superconducting-magnetic hybrid Josephson junctions

January 9, 2015
Author(s)
Burm Baek, William H. Rippard, Matthew R. Pufall, Samuel P. Benz, Stephen E. Russek, Horst Rogalla, Paul D. Dresselhaus
Combining superconducting and magnetic materials to create novel superconducting devices has been motivated by the discovery of the Josephson critical current (Ics) oscillations with magnetic layer thickness and the demonstration of devices with switchable

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

Junction Yield Analysis for 10 V Programmable Josephson Voltage Standard Devices

December 5, 2014
Author(s)
Anna E. Fox, Paul D. Dresselhaus, Alain Rufenacht, Aric W. Sanders, Samuel P. Benz
Analysis of the Josephson junction yield in the National Institute of Standards and Technology 10 V Programmable Josephson Voltage Standard (PJVS) has been performed by fabricating and measuring over 25 million Nb/NbxSi1-x/Nb junctions. Using the 265,116

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

1 V Josephson arbitrary waveform synthesizer

September 17, 2014
Author(s)
Samuel P. Benz, Steven B. Waltman, Anna E. Fox, Paul D. Dresselhaus, Alain Rufenacht, Jason M. Underwood, Charles J. Burroughs
A quantum-accurate waveform with a root-mean-square (RMS) output amplitude of 1 V has been synthesized for the first time. This four-fold increase in voltage over previous systems was achieved through developments and improvements in bias electronics

AC Waveform Source Referenced to a Programmable Josephson Voltage Standard

August 24, 2014
Author(s)
Alain Rufenacht, Charles J. Burroughs, Bryan C. Waltrip, Stephane P. Solve, Paul D. Dresselhaus, Samuel P. Benz
We are integrating an AC waveform source into our Programmable Josephson Voltage Standard system (PJVS). The objective is to provide a convenient, highly automated quantum-referenced source for ac voltage metrology that does not require the use of a

Measurement of the Boltzmann Constant with Noise Thermometry at NIM

August 24, 2014
Author(s)
Jifeng Qu, Kunli Zhou, Horst Rogalla, Samuel Benz, Yunfeng Fu
Since 2010 we have been developing a quantum-voltage-calibrated Johnson noise thermometer at NIM to measure the Boltzmann constant k. With recent improvements in grounding and shielding of the electronics, and matching of the noise sources and transmission

Systematic Error Resolved in NIST Johnson Noise Thermometer

August 24, 2014
Author(s)
Alessio Pollarolo, Weston L. Tew, Horst Rogalla, Samuel P. Benz
In the Johnson Noise Thermometry approach, Boltzmann’s constant k is obtained as the ratio of the noise power measured across a sense resistor at the triple point of water and the noise power measured for a synthesized reference waveform. The reference

Hybrid superconducting-magnetic memory device using competing order parameters

May 28, 2014
Author(s)
Burm Baek, William H. Rippard, Samuel P. Benz, Stephen E. Russek, Paul D. Dresselhaus
The quantum behavior of Josephson junctions is often exploited to produce superconducting devices with outstanding performance. Josephson junctions can also be used in circuits that perform logic operations in picoseconds and may enable high-performance

Improvements to the Johnson Noise Thermometry System for Measurements at 505 – 800 K

September 12, 2013
Author(s)
Weston L. Tew, Kazuaki Yamazawa, Samuel P. Benz, Alessio Pollarolo, Horst Rogalla, Paul D. Dresselhaus
The National Institute of Standards and Technology (NIST) is currently using Johnson noise thermometry (JNT) to determine the deviations of the International Temperature Scale of 1990 (ITS-90) from the thermodynamic temperature in the range of 505–933 K

Development of a Quantum-Voltage-Calibrated Noise Thermometer at NIM

September 11, 2013
Author(s)
Jifeng Qu, Samuel Benz, Jianqiang Zhang, Horst Rogalla, Yang Fu, Alessio Pollarolo, Jintao Zhang
A quantum-voltage-calibrated Johnson-noise thermometer was developed at NIM, which measures the Boltzmann constant k through comparing the thermal noise across a 100  sense resistor at the temperature of the triple point water to the comb-like voltage

Johnson-noise thermometry based on a quantized-voltage noise source at NIST

September 11, 2013
Author(s)
Alessio Pollarolo, Tae H. Jeong, Samuel Benz, Paul Dresselhaus, Horst Rogalla, Weston L. Tew
Johnson Noise Thermometry is an electronic approach to measuring temperature. For several years, NIST has been developing a switching-correlator-type Johnson-noise thermometer that uses a quantized voltage noise source as an accurate voltage reference

Direct Comparison of two NIST PJVS systems at 10 V

August 27, 2013
Author(s)
Stephane Solve, Alain Rufenacht, Charles J. Burroughs, Samuel Benz
Two NIST Programmable Josephson Voltage Standard (PJVS) systems have been directly compared at 10V using different nanovoltmeters at the temperature of the laboratory. These PJVS systems use arrays double-stacked superconducting-niobium Josephson junctions

Properties of magnetic barrier structures for superconducting-magnetic hybrid Josephson junctions

July 7, 2013
Author(s)
Burm Baek, Samuel P. Benz, William H. Rippard, Stephen E. Russek, Paul D. Dresselhaus, Horst Rogalla, Matthew R. Pufall
If Josephson and spintronic technologies can be successfully integrated to produce a cryogenic memory that can be controlled with single-flux quantum pulses, then they may enable ultra-low-power, high-speed computing. We have developed hybrid Josephson

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

Flat Frequency Response in the Electronic Measurement of the Boltzmann Constant

June 1, 2013
Author(s)
Jifeng Qu, Horst Rogalla, Yang Fu, Jianqiang Zhang, Alessio Pollarolo, Samuel Benz
A new quantum voltage calibrated Johnson noise thermometer (JNT) was developed at NIM to demonstrate the electrical approach that determines the Boltzmann constant k by comparing electrical and thermal noise power. A measurement with an integration period