Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

IEEE Transactions on Applied Superconductivity

Quantum-Derived Voltage Waveform Synthesis With Pulse-Driven High-Transition-Temperature Josephson Junctions

Adam C. Weis, Nathan E. Flowers-Jacobs, S. J. Berkowitz, Horst Rogalla, Samuel P. Benz

Published Jul 8, 2020• 1 citation
Publisher

Abstract

Microwave-driven Josephson junction arrays are the basis for dc and ac voltage standards, whose accuracy derives from quantized voltage pulses. These pulses are also used to synthesize voltage-noise reference signals that are used in noise thermometry systems. This article describes our recent demonstration of voltage synthesis in a high-transition-temperature YBa2Cu3O7-δjunction circuit.

DOI
10.1109/tasc.2020.3007777

Related papers

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

Adam C. Weis, Nathan E. Flowers-Jacobs, E.Y. Cho +6 more

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-temperature YBCO junctions.

IEEE International Superconductive Electronics Conference (ISEC)•Jul 1, 2019•0 citations

A pulse-driven Josephson arbitrary waveform synthesis system as a quantum AC voltage standard in KRISS

Yonuk Chong, Woon Young Song, Jung-Suk Choi +4 more

We report our progress in the Josephson arbitrary waveform synthesis system in KRISS. The system is based on the pulse-driven Josephson junction array, and currently we routinely produce arbitrary waveforms up to 100 mVrms amplitude with distortions smaller than 100 dBc. Precision waveform synthesis results are presented. Our future works will include AC-DC thermal transfer measurement and quantum noise source for Johnson noise thermometry.

•Jun 1, 2010•3 citations

Josephson-based quantum voltage standards – an ongoing success story

Ralf Behr, Stephan Bauer, Marco Kraus +2 more

The past few decades have witnessed great progress being made from the first voltage standards based on arrays of Josephson junctions. Continuous improvements in the fabrication process have increased the quality and “user-friendliness” of these superconducting circuits. Combined with the improvements in measuring electronics, the range of applications of Josephson-based measurements with unmatched precision has extended from DC into AC voltage metrology for signal frequencies up to 500 kHz. In this poster we will present several Josephson-based measurement systems developed for metrology applications. Two versions of quantum AC standards will be used as Josephson references: Programmable Josephson Voltage Standards (PJVS), which are based on serial arrays with up to 300,000 Josephson junctions, and pulse-driven arrays with more than 50,000 junctions, typically referred to as Josephson Arbitrary Waveform Synthesizers (JAWS). PJVS can reach amplitudes of up to 80 V, while pulse-driven arrays can reach up to 1 V or even 4 V. The advantage of pulse-driven Josephson voltage standards is that they are ideally suited as quantum-based voltage synthesizers for arbitrary waveforms or sine waves with high spectral purity. Therefore, they can be used directly to characterize or calibrate ADCs. In addition, JAWS are particularly useful in Josephson impedance bridges, which perform automated impedance calibrations at the 10-9 uncertainty level over a wide frequency range from 50 Hz to 80 kHz in a single bridge. We will further show how PJVS are used in commercial quantum voltmeters for DC and AC voltages and are typically used as quantum voltage references in measurement systems. Using differential sampling based on PJVS, uncertainties at the level of a few parts in 108 for frequencies up to the kHz range can be achieved. Such quantum-based AC voltage calibrations are at least 30 times faster than conventional AC-DC transfer and offer even better uncertainties. This idea has been quickly adopted by many National Metrology Institutes to establish such systems for AC voltage calibrations. As an example, the BIPM will now start worldwide onsite comparisons to ensure the uniformity of the new method which we introduced in 2006. But developments continue. Recently, a sub-sampling technique was used to extend the frequency range of the AC quantum voltmeter to up to 100 kHz with uncertainties below 5 parts in 106. In addition, a novel method, also for differential sampling, enables the measurement of arbitrary waveforms and the calibration of specific tones. Our poster will provide an overview of these Josephson-based metrological applications and present the latest developments from this fast-developing area.

•Jan 1, 2025•0 citations

Pulse-Driven Josephson Junction Arrays for High-Precision AC-Voltage Synthesis of Unipolar and Bipolar Waveforms

M. Schubert, G. Wende, T. May +5 more

The paper is about development of the lumped Josephson junction arrays (JJAs) for the generation of accurate quantum-based ac voltages. By using semiconductor pattern generators, it was possible to synthesize unipolar and bipolar waveforms with amplitudes of almost 10 mV and frequencies of up to 122 kHz. Higher harmonics and other unwanted noise signals were suppressed by -90 dBc. Because of the unique layout of our JJA, it was possible to connect the circuit directly to the ground, thereby eliminating common-mode signals

IEEE Transactions on Instrumentation and Measurement•Mar 16, 2007•3 citations

Multitone Waveform Synthesis With a Quantum Voltage Noise Source

Samuel P. Benz, Paul D. Dresselhaus, Charles J. Burroughs

We have developed a quantum voltage noise source (QVNS) based on pulse-driven Josephson arrays and optimized its waveform synthesis for use with Johnson noise thermometry (JNT). The QVNS synthesizes multitone waveforms with equal amplitude harmonic tones and random relative phases in order to characterize the amplitude-frequency response of the analog and digital electronics of the JNT system. We describe the QVNS circuit design and operation, including the lumped-array Josephson-junction circuit and the unipolar bias technique. In particular, we describe the primary design considerations that determine the voltage accuracy of the harmonic tones.

IEEE Transactions on Applied Superconductivity•Nov 17, 2010•29 citations

Development of quantum voltage noise source chip for precision measurement of Boltzmann constant

Wang Lan-Ruo, Yuan Zhong, Jinjin Li +7 more

The Johnson noise thermometer is used to precisely measure Boltzmann constant by comparing the thermal noise caused by charge movement and the quantized voltage reference noise synthesized by the quantum voltage noise source (QVNS). The QVNS signal is synthesized based on quantized voltage pulses produced by two channels of superconducting Josephson junction arrays, which are designed for cross-correlation electronics. The Nb/NbxSi1-x/Nb Josephson junction is used as a core device of QVNS chip in this work for its non-hysteretic current-voltage (I-V) characteristics and conveniently adjustable barrier parameters.In this paper, we present the design consideration, fabrication process, and measurement results of the QVNS chip. The QVNS chip contains two Josephson junction arrays, each consists of four 6 μm×12 μm junctions and is embedded in a 50 Ω coplanar waveguide transmission line. The random noise in signals from the two driven channels is eliminated by cross-correlation, and then an accurate quantum noise is obtained. Test chips with different areas of Josephson junctions are also designed on the same mask, aiming at estimating the variation range of Ic. The typical fabrication process for voltage standard chips in our laboratory is used for preparing the QVNS chip.The sample is measured at 4.2 K. The DC I-V curve shows that the critical current Ic is 6.1 mA. The I-V characteristics of the junctions under 5 GHz microwave radiation are measured. For a series array of four junctions, a 41.44 μV one-stage Shapiro step is observed. Calculation shows that the error between the measurement and theoretical value of 41.36 μV is about 1.9‰, which means that the QVNS chip performs well under microwave radiation and can be used for synthesizing the AC quantum voltage reference noise.A single-frequency 100 kHz sinusoidal waveform is synthesized by the QVNS chip under pulse driven signal. A spectrum of the synthesized sinusoidal waveform shows a single peak, which means that the digital pulse signal is perfectly filtered by Josephson junction arrays and the synthesized signals possess quantum accuracy. The results indicate that our chip has good dynamic response and works well in synthesizing a single-frequency AC quantum voltage signal. This work can provide core devices for the noise thermometry system and support the precise measurement of Boltzmann constant as well as redefinition of Kelvin in future. As a next step, the design and package will be further improved, and the probe module will be optimized to reduce the measurement uncertainty.

Acta Physica Sinica•Jan 1, 2018•3 citations
Microwave-driven Josephson junction arrays are the basis for dc and ac voltage standards, whose accuracy derives from quantized voltage pulses. These pulses are also used to synthesize voltage-noise reference signals that are used in noise thermometry systems. This article describes our recent demonstration of voltage synthesis in a high-transition-temperature YBa2Cu3O7-δjunction circuit.
The past few decades have witnessed great progress being made from the first voltage standards based on arrays of Josephson junctions. Continuous improvements in the fabrication process have increased the quality and “user-friendliness” of these superconducting circuits. Combined with the improvements in measuring electronics, the range of applications of Josephson-based measurements with unmatched precision has extended from DC into AC voltage metrology for signal frequencies up to 500 kHz. In this poster we will present several Josephson-based measurement systems developed for metrology applications. Two versions of quantum AC standards will be used as Josephson references: Programmable Josephson Voltage Standards (PJVS), which are based on serial arrays with up to 300,000 Josephson junctions, and pulse-driven arrays with more than 50,000 junctions, typically referred to as Josephson Arbitrary Waveform Synthesizers (JAWS). PJVS can reach amplitudes of up to 80 V, while pulse-driven arrays can reach up to 1 V or even 4 V. The advantage of pulse-driven Josephson voltage standards is that they are ideally suited as quantum-based voltage synthesizers for arbitrary waveforms or sine waves with high spectral purity. Therefore, they can be used directly to characterize or calibrate ADCs. In addition, JAWS are particularly useful in Josephson impedance bridges, which perform automated impedance calibrations at the 10-9 uncertainty level over a wide frequency range from 50 Hz to 80 kHz in a single bridge. We will further show how PJVS are used in commercial quantum voltmeters for DC and AC voltages and are typically used as quantum voltage references in measurement systems. Using differential sampling based on PJVS, uncertainties at the level of a few parts in 108 for frequencies up to the kHz range can be achieved. Such quantum-based AC voltage calibrations are at least 30 times faster than conventional AC-DC transfer and offer even better uncertainties. This idea has been quickly adopted by many National Metrology Institutes to establish such systems for AC voltage calibrations. As an example, the BIPM will now start worldwide onsite comparisons to ensure the uniformity of the new method which we introduced in 2006. But developments continue. Recently, a sub-sampling technique was used to extend the frequency range of the AC quantum voltmeter to up to 100 kHz with uncertainties below 5 parts in 106. In addition, a novel method, also for differential sampling, enables the measurement of arbitrary waveforms and the calibration of specific tones. Our poster will provide an overview of these Josephson-based metrological applications and present the latest developments from this fast-developing area.
The paper is about development of the lumped Josephson junction arrays (JJAs) for the generation of accurate quantum-based ac voltages. By using semiconductor pattern generators, it was possible to synthesize unipolar and bipolar waveforms with amplitudes of almost 10 mV and frequencies of up to 122 kHz. Higher harmonics and other unwanted noise signals were suppressed by -90 dBc. Because of the unique layout of our JJA, it was possible to connect the circuit directly to the ground, thereby eliminating common-mode signals
We have developed a quantum voltage noise source (QVNS) based on pulse-driven Josephson arrays and optimized its waveform synthesis for use with Johnson noise thermometry (JNT). The QVNS synthesizes multitone waveforms with equal amplitude harmonic tones and random relative phases in order to characterize the amplitude-frequency response of the analog and digital electronics of the JNT system. We describe the QVNS circuit design and operation, including the lumped-array Josephson-junction circuit and the unipolar bias technique. In particular, we describe the primary design considerations that determine the voltage accuracy of the harmonic tones.
The Johnson noise thermometer is used to precisely measure Boltzmann constant by comparing the thermal noise caused by charge movement and the quantized voltage reference noise synthesized by the quantum voltage noise source (QVNS). The QVNS signal is synthesized based on quantized voltage pulses produced by two channels of superconducting Josephson junction arrays, which are designed for cross-correlation electronics. The Nb/NbxSi1-x/Nb Josephson junction is used as a core device of QVNS chip in this work for its non-hysteretic current-voltage (I-V) characteristics and conveniently adjustable barrier parameters.In this paper, we present the design consideration, fabrication process, and measurement results of the QVNS chip. The QVNS chip contains two Josephson junction arrays, each consists of four 6 μm×12 μm junctions and is embedded in a 50 Ω coplanar waveguide transmission line. The random noise in signals from the two driven channels is eliminated by cross-correlation, and then an accurate quantum noise is obtained. Test chips with different areas of Josephson junctions are also designed on the same mask, aiming at estimating the variation range of Ic. The typical fabrication process for voltage standard chips in our laboratory is used for preparing the QVNS chip.The sample is measured at 4.2 K. The DC I-V curve shows that the critical current Ic is 6.1 mA. The I-V characteristics of the junctions under 5 GHz microwave radiation are measured. For a series array of four junctions, a 41.44 μV one-stage Shapiro step is observed. Calculation shows that the error between the measurement and theoretical value of 41.36 μV is about 1.9‰, which means that the QVNS chip performs well under microwave radiation and can be used for synthesizing the AC quantum voltage reference noise.A single-frequency 100 kHz sinusoidal waveform is synthesized by the QVNS chip under pulse driven signal. A spectrum of the synthesized sinusoidal waveform shows a single peak, which means that the digital pulse signal is perfectly filtered by Josephson junction arrays and the synthesized signals possess quantum accuracy. The results indicate that our chip has good dynamic response and works well in synthesizing a single-frequency AC quantum voltage signal. This work can provide core devices for the noise thermometry system and support the precise measurement of Boltzmann constant as well as redefinition of Kelvin in future. As a next step, the design and package will be further improved, and the probe module will be optimized to reduce the measurement uncertainty.