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

A Cross-Type SNS Junction Array for a Quantum-Based Arbitrary Waveform Synthesizer

M. Schubert, T. May, G. Wende, H.‐G. Meyer

Published Jun 1, 2005• 19 citations
Publisher

Abstract

Central to quantum-based arbitrary waveform synthesizers is a Josephson junction array driven by short pulses. Its linear dimensions should be small compared to the line wavelength in order to generate an ac voltage with quantum accuracy. Therefore, we use coplanar strip transmission lines to integrate a large number of cross-type SNS Josephson junctions into multiple parallel arrays. First measurements show that a circuit with 1,760 junctions exhibits Shapiro steps over a large frequency range. By using pulse driving the chip generates unipolar voltages up to 6.4 mV at a clock frequency of 3.5 GHz, the maximum frequency of the available pulse pattern generator.

DOI
10.1109/tasc.2005.850072

Related papers

A Lumped Array Josephson Pulse Quantizer for Quantum-Based Arbitrary Waveform Synthesizers

M. Schubert, G. Wende, T. May +1 more

Central to quantum-based arbitrary waveform synthesizers is the Josephson pulse quantizer. Its linear dimensions should be small compared to the line wavelength in order to generate an ac voltage with quantum accuracy. Therefore, we use coplanar strip transmission lines to integrate a large number of Josephson junctions into a short array

Conference on Precision Electromagnetic Measurements•Jun 1, 2004•4 citations

SNS Josephson Junction Series Arrays for the Josephson Arbitrary Waveform Synthesizer

Oliver Kieler, J. Kohlmann, Ralf Behr +3 more

The Josephson arbitrary waveform synthesizer (JAWS) allows AC voltages to be generated with fundamental accuracy. Lumped arrays of superconductor/normal conductor/superconductor (SNS) Josephson junctions were developed and investigated for this application. Combining electron-beam lithography and chemical-mechanical polishing, series arrays of sub-micrometer SNS junctions consisting of Nb/HfTi/Nb were fabricated. The junction size varied from 0.04 mum2to 4 mum2in series arrays up to 2560 junctions in different microwave designs. Stable Shapiro steps are generated in a frequency range from 5 GHz to 20 GHz using continuous microwave irradiation. Using a simple pulse pattern at different pulse repetition frequencies, the arrays show current-voltage characteristics with flat Shapiro steps. Sinusoidal AC voltages were synthesized using a commercial pulse pattern generator. Peak-to-zero voltages of some mV for frequencies below 1 kHz were achieved. Higher harmonics were measured to be more than 80 dB below the fundamental tone. The behavior of the arrays was investigated in more detail by measuring the amplitude-frequency spectra.

IEEE Transactions on Applied Superconductivity•Jun 1, 2007•23 citations

Improved design of superconductor/normal conductor/superconductor Josephson junction series arrays for an ac Josephson voltage standard

Oliver Kieler, J. Kohlmann, Franz Müller

Superconductor/normal conductor/superconductor (SNS) Josephson junction series arrays are the subject of research for the realization of a Josephson arbitrary waveform synthesizer (JAWS) based on pulse-driven Josephson junctions. Lumped arrays of SNS Josephson junctions are investigated for this application at the Physikalisch-Technische Bundesanstalt (PTB). The series arrays consisting of Nb/HfTi/Nb SNS junctions are embedded in the center line of a coplanar waveguide transmission line. To increase the ac output voltage, the Josephson junction series array is designed as a meander-like structure. A broadband response of the arrays is required for the complex pulse operation of the JAWS. The arrays are investigated by dc measurements and for test purposes under continuous microwave irradiation at different frequencies. Flat Shapiro steps were measured for meander-like series arrays with 21 parallel lines containing up to 10 752 junctions. A sine wave with a frequency of 2.5 kHz and a peak voltage of 214 mV Peak was synthesized under pulse mode operation.

Superconductor Science and Technology•Oct 18, 2007•28 citations

Sub-$\mu{\rm m}$ SNS Josephson Junction Arrays for the Josephson Arbitrary Waveform Synthesizer

Oliver Kieler, Ricardo Iuzzolino, J. Kohlmann

The experimental set-up of a Josephson arbitrary waveform synthesizer (JAWS) has been further optimized to generate AC voltages with fundamental accuracy. Josephson junction series arrays for the JAWS, consisting of sub-mum SNS type junctions (superconductor-normal conductor-superdonductor), are fabricated using a technology which combines electron-beam lithography and chemical-mechanical polishing. Bipolar pulses are realized by the superposition of unipolar pulses from a pulse pattern generator and a continuous sinusoidal microwave provided by a signal generator. A second-order delta-sigma modulator is optimized to generate a high-quality pulse code.

IEEE Transactions on Applied Superconductivity•Jun 1, 2009•36 citations

SNS josephson junction series arrays for the Josephson Arbitrary Waveform Synthesizer

J. Kohlmann, Oliver Kieler, Ricardo Iuzzolino +3 more

AC voltages and arbitrary waveforms are synthesized by Josephson junctions operated by short current pulses. Series arrays of intrinsically shunted SNS Josephson junctions were developed and investigated for applications in this Josephson Arbitrary Waveform Synthesizer (JAWS). Amplitudes above 200 mV were generated by series arrays consisting of more than 10,000 junctions arranged in a meander-like design.

Conference on Precision Electromagnetic Measurements•Jun 1, 2008•3 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
Central to quantum-based arbitrary waveform synthesizers is a Josephson junction array driven by short pulses. Its linear dimensions should be small compared to the line wavelength in order to generate an ac voltage with quantum accuracy. Therefore, we use coplanar strip transmission lines to integrate a large number of cross-type SNS Josephson junctions into multiple parallel arrays. First measurements show that a circuit with 1,760 junctions exhibits Shapiro steps over a large frequency range. By using pulse driving the chip generates unipolar voltages up to 6.4 mV at a clock frequency of 3.5 GHz, the maximum frequency of the available pulse pattern generator.
The Josephson arbitrary waveform synthesizer (JAWS) allows AC voltages to be generated with fundamental accuracy. Lumped arrays of superconductor/normal conductor/superconductor (SNS) Josephson junctions were developed and investigated for this application. Combining electron-beam lithography and chemical-mechanical polishing, series arrays of sub-micrometer SNS junctions consisting of Nb/HfTi/Nb were fabricated. The junction size varied from 0.04 mum2to 4 mum2in series arrays up to 2560 junctions in different microwave designs. Stable Shapiro steps are generated in a frequency range from 5 GHz to 20 GHz using continuous microwave irradiation. Using a simple pulse pattern at different pulse repetition frequencies, the arrays show current-voltage characteristics with flat Shapiro steps. Sinusoidal AC voltages were synthesized using a commercial pulse pattern generator. Peak-to-zero voltages of some mV for frequencies below 1 kHz were achieved. Higher harmonics were measured to be more than 80 dB below the fundamental tone. The behavior of the arrays was investigated in more detail by measuring the amplitude-frequency spectra.
Superconductor/normal conductor/superconductor (SNS) Josephson junction series arrays are the subject of research for the realization of a Josephson arbitrary waveform synthesizer (JAWS) based on pulse-driven Josephson junctions. Lumped arrays of SNS Josephson junctions are investigated for this application at the Physikalisch-Technische Bundesanstalt (PTB). The series arrays consisting of Nb/HfTi/Nb SNS junctions are embedded in the center line of a coplanar waveguide transmission line. To increase the ac output voltage, the Josephson junction series array is designed as a meander-like structure. A broadband response of the arrays is required for the complex pulse operation of the JAWS. The arrays are investigated by dc measurements and for test purposes under continuous microwave irradiation at different frequencies. Flat Shapiro steps were measured for meander-like series arrays with 21 parallel lines containing up to 10 752 junctions. A sine wave with a frequency of 2.5 kHz and a peak voltage of 214 mV Peak was synthesized under pulse mode operation.
Sub-μm\mu{\rm m}μm SNS Josephson Junction Arrays for the Josephson Arbitrary Waveform Synthesizer
The experimental set-up of a Josephson arbitrary waveform synthesizer (JAWS) has been further optimized to generate AC voltages with fundamental accuracy. Josephson junction series arrays for the JAWS, consisting of sub-mum SNS type junctions (superconductor-normal conductor-superdonductor), are fabricated using a technology which combines electron-beam lithography and chemical-mechanical polishing. Bipolar pulses are realized by the superposition of unipolar pulses from a pulse pattern generator and a continuous sinusoidal microwave provided by a signal generator. A second-order delta-sigma modulator is optimized to generate a high-quality pulse code.
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