U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Horst Rogalla (Assoc)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 27

Johnson Noise Thermometry

September 3, 2019
Author(s)
Weston L. Tew, Jifeng Qu, K L. Zhou, Samuel P. Benz, Horst Rogalla, David R. White
Johnson noise thermometers infer thermodynamic temperature from measurements of the thermally-induced current fluctuations that occur in all electrical conductors. This paper reviews the status of Johnson noise thermometry and its prospects for both

Pulse-Driven High-Tc Josephson Junctions for Quantum Voltage Devices

July 28, 2019
Author(s)
Adam C. Weis, Nathan E. Flowers-Jacobs, E Y. Choi, H Li, J C. LeFebvre, Shane Cybart, Stuart Berkowitz, Horst Rogalla, Samuel P. Benz
Josephson junction arrays are the basis for quantum-accurate dc and ac voltage standards, including artificial voltage-noise references used in noise thermometry. I will describe our recent progress towards voltage synthesis using high-transition

The NIST Johnson noise thermometry system for the determination of the Boltzmann constant

December 29, 2017
Author(s)
Nathan Flowers-Jacobs, Alessio Pollarolo, Kevin Coakley, Adam C. Weis, Anna Fox, Horst Rogalla, Weston L. Tew, Samuel Benz
In preparation for the redefinition of the International System of Units (SI), five different electronic measurements of the Boltzmann constant have been performed using different Johnson noise thermometry (JNT) systems over the past seven years. In this

A Boltzmann Constant Determination Based on Johnson Noise Thermometry

August 10, 2017
Author(s)
Nathan E. Flowers-Jacobs, Alessio Pollarolo, Kevin J. Coakley, Anna E. Fox, Horst Rogalla, Weston L. Tew, Samuel P. Benz
A value for the Boltzmann constant was measured electronically using an improved version of the Johnson Noise Thermometry (JNT) system at the National Institute of Standards and Technology (NIST), USA. This system is different from prior ones, including

An improved electronic measurement of the Boltzmann constant by Johnson noise thermometry

July 18, 2017
Author(s)
Jifeng Qu, Samuel Benz, Kevin Coakley, Horst Rogalla, Weston L. Tew, David R. White, Kunli Zhou, Zhenyu Zhou
Recent measurements using acoustic gas thermometry have determined the value of the Boltzmann constant, k, with a relative uncertainty less than 110-6. These results have been supported by a measurement with a relative uncertainty of 1.910-6 made with

Improved spectra aberration in the Johnson Noise Thermometry

July 9, 2016
Author(s)
Alessio Pollarolo, Horst Rogalla, Anna Fox, Kevin J. Coakley, Weston L. Tew, Samuel P. Benz
SPECTRAL ABERRATION HAS BEEN FOR A LONG TIME THE MAIN SOURCE OF UNCERTAINTY IN THE JOHNSON NOISE THERMOMETRY APPROACH TO MEASURING THE BOLTZMANN CONSTANT. RECENTLY, WITH NEWLY DEVELOPED HARDWARE AND THE INTRODUCTION OF A NOVEL FITTING ALGORITHM FOR

Improved electronic measurement of the Boltzmann constant by Johnson noise Thermometry

August 19, 2015
Author(s)
Weston L. Tew, Samuel P. Benz, Horst Rogalla, Alessio Pollarolo, David R. White, Jifeng Qu, Kunli Zhou
The unit of thermodynamic temperature, the kelvin, will be redefined in 2018 by fixing the value of the Boltzmann constant, k. The present CODATA recommended value of k is determined predominantly by acoustic gas-thermometry results. To provide a value of

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

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

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

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

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

Flat frequency response in the electronic measurement of the Boltzmann constant

July 1, 2012
Author(s)
Jifeng Qu, Samuel Benz, Yang Fu, Jianqiang Zhang, Horst Rogalla, Alessio Pollarolo
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 integration period of

An electronic measurement of the Boltzmann constant

March 30, 2011
Author(s)
Samuel P. Benz, Alessio Pollarolo, Jifeng Qu, Horst Rogalla, Chiharu Urano, Weston L. Tew, Paul D. Dresselhaus, D. R. White
The Boltzmann constant was measured by comparing the Johnson noise of a resistor at the triple point of water with a quantum-based voltage reference signal generated with a superconducting Josephson-junction waveform synthesizer. The measured value of k =

Reduced Nonlinearity Effect on the Electronic Measurement of the Boltzmann Constant

January 10, 2011
Author(s)
Jifeng Qu, Samuel Benz, Alessio Pollarolo, Horst Rogalla
NIST has developed a quantum voltage noise source (QVNS) calibrated Johnson noise thermometer (JNT) to provide a new electronic measurement technique for determining the Boltzmann constant. Improvements in electronics and synthesized noise waveforms have

Development of a Four-channel System for Johnson Noise Thermometry

December 30, 2010
Author(s)
Alessio Pollarolo, Chiharu Urano, Paul Dresselhaus, Jifeng Qu, Horst Rogalla, Samuel Benz
Long integration time is necessary to reach low uncertainty when measuring temperature through Johnson Noise Thermometry (JNT). The main goal of the NIST JNT experiment is to achieve a 6×10-6 relative uncertainty in the measurement of the water triple

Development of a Four-channel System for Johnson Noise Thermometry

June 13, 2010
Author(s)
Alessio Pollarolo, Jifeng Qu, Horst Rogalla, Paul Dresselhaus, Samuel Benz
Long integration time is necessary to reach low uncertainty when measuring temperature through Johnson Noise Thermometry (JNT). The main goal of the NIST JNT experiment is to achieve a 6 10-6 relative uncertainty in the measurement of the water triple

Reduced Nonlinearities in the NIST Johnson Noise Thermometry System

June 13, 2010
Author(s)
Jifeng Qu, Samuel Benz, Alessio Pollarolo, Horst Rogalla
Improved electronics and synthesized noise waveforms for the NIST quantum-voltage-standard- calibrated Johnson noise thermometer (JNT) have lead to reduced uncertainty in the temperature measurement. Recent measurements show that some of the distortion in