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

Octopux: an advanced automated setup for testing superconductor circuits

Dmitry Y. Zinoviev, Y.A. Polyakov

Published Jun 1, 1997• 106 citations
Publisher

Abstract

An integrated multipurpose setup for the automated testing of superconductor devices and circuits has been designed, implemented, and installed in the RSFQ Laboratory of the State University of New York at Stony Brook. The extendable and modular design of the setup allows a wide variety of low-frequency superconductor experiments to be carried out including those that require immediate interaction between the setup and the researcher.

DOI
10.1109/77.622039

Related papers

[INVITED] Test setup for functional superconducting logic circuits

Pascal Febvre

A test setup bench is being implemented in the laboratory to test digital superconducting circuits under various conditions of operation. I will present in a first step the computer-controlled test environment developed to extract the main parameters of Josephson devices used in digital circuits and to test the circuits at low frequencies. Some results obtained on some Josephson junction arrays and circuits will be shown to illustrate this part. In a second step, I will review the microwave and optical signal feeds and readout that are under development in order to trigger and diagnose digital circuits at higher frequencies. Finally, a study of the expected performance of an on-chip diagnostic system aimed at discriminating different signal waveforms generated by superconducting digital circuits will be presented.

•Nov 29, 2004•0 citations

Results From the ColdFlux Superconductor Integrated Circuit Design Tool Project

Coenrad Johann Fourie, Kyle Jackman, Johannes A. Delport +20 more

In five and a half years, the ColdFlux project under the IARPA SuperTools program pushed the boundaries of digital and analog superconductor electronic design automation (S-EDA) tools. The SuperTools program demanded significant beyond-state-of-the-art deliverables in four main areas: RTL synthesis, architectures, and verification; analog design and layout synthesis; physical design and test; and technology CAD and cell library design. Through the work of academic groups scattered over four continents, the ColdFlux effort forged into a powerful set of open-source and commercial S-EDA tools unlike any before, rivaled only by a commercial toolchain from Synopsys under the same SuperTools umbrella. We present an overview of the tools from where we started to the eventual project deliverables. These include powerful simulation and extraction engines, magnetic field and flux trapping analysis, advanced clocking methods, multi-chip interface extraction and verification, unified multi-layer design-rule compliant track blocks for automated place and route of both rapid single flux quantum (RSFQ) and adiabatic quantum-flux-parametron (AQFP) cells, models and tools for validation and test, multi-bit single flux quantum (SFQ) cells, architecture innovations for full CPU designs and more. Comprehensive cell libraries and a process design kit (PDK) were developed with the ColdFlux tools. The AQFP cell library features a logically rich collection of 80+ cells, including 3- and 5-input logic gates, signal-driving boosters, and refined RSFQ-to-AQFP interfaces, while the RSFQ library has 30+ cells. Finally, we discuss how the full toolchain enables and enhances the superconductor IC design process.

IEEE Transactions on Applied Superconductivity•Aug 18, 2023•21 citations

Ultra-High-Speed Superconductor Digital Circuits

Vasili K. Semenov

Josephson junction integrated circuits using Rapid Single-Flux-Quantum (RSFQ) logic are capable of performing logic operations at ultrahigh clock frequencies in excess of 100 GHz [1]. In this report I will describe recent progress in design, fabrication, and testing of several circuits of this family.

Ultrafast Electronics and Optoelectronics (UEO)•Jan 1, 1995•0 citations

Superconductor Integrated Circuit (IC) Testing With the Integrated Cryogenic Electronics Testbed (ICE-T)

Vladimir Valentinovich Dotsenko, Benjamin Chonigman, Anubhav Sahu +4 more

Future development of superconductor digital and mixed-signal ICs requires extensive testing with a large number of input/output (I/O) lines for applying independent bias controls, injecting test signals, and monitoring outputs of different sub-circuits. There is a growing need for a standardized test apparatus for a variety of complex superconducting chips and multichip modules (MCMs). Such a test apparatus must support many I/O lines, be easy and cost-effective to operate, and support prolonged automated testing. Existing test apparatus include liquid He cryoprobes and cryocooled custom digital-RF systems, both of which have drawbacks. Liquid He cryoprobes with universal wiring, such as 40 or 80 coaxial cables, are convenient to use. Cooled by immersion in a tank filled with liquid He, these cryoprobes allow rapid cool-down and warm-up. However, large consumption of liquid He, the cost of which has been steadily increasing worldwide, makes this solution rather expensive and wasteful. On the other hand, one can exploit the modular reconfigurability of HYPRES' digital-RF receiver product to create a testbed for different ICs. Such a system uses the smallest commercially available closed-cycle refrigerator (~1.2 kW) and has negligible operating cost. However, reconfiguration takes time and expertise since these products are specially designed with customized chip package and wiring to minimize the thermal load on the cryocooler. These low-maintenance systems are ideal for prolonged operation of a single chip, which is invaluable for superconductor electronics system developers and end-users. The integrated cryoelectronics testbed (ICE-T) combines the advantages of the liquid He cryoprobe and the cryocooled digital-RF product. By using a more powerful, commercially available, electrically powered closed-cycle refrigerator (7 kW), ICE-T alleviates the thermal constraints on wiring while maintaining very low operating cost. By separating the electrical and thermal subsystems, it maintains modularity without sacrificing the universality of the cryoprobe. A set of universal and custom electrical modules can be independently built and inserted in ICE-T. Universal inserts with 40 and 80 coaxial cables accommodate all chips with standard I/O pads like the familiar liquid He cryoprobes. Custom inserts for different classes of chips and MCMs are designed and built according to user requirements and specifications. The utility of the ICE-T was successfully demonstrated by testing a benchmark superconducting digital circuit at low frequency and an analog-to-digital converter chip clocked above 20 GHz.

IEEE Transactions on Applied Superconductivity•Jan 30, 2017•14 citations

New RSFQ circuits (Josephson junction digital devices)

Stanislav V. Polonsky, Vasili K. Semenov, P. Bunyk +7 more

Several novel circuits of the rapid single-flux-quantum (RSFQ) family of Josephson-junction digital devices have been designed, fabricated using a 2.5- mu m 1000-A/cm/sup 2/ Nb trilayer technology, and tested at low frequencies. Numerical simulation and measurements have shown that these circuits have considerably wider parameter margins, due to application of several novel design methods. The authors have also carried out an experiment to measure the rate of errors in a simple RSFQ circuit including an inverter, confluence buffer, and Josephson transmission line. Near the middle of the parameter window at 4.2 K, the error probability was definitely lower than 3*10/sup -15/ per logic operation, despite experimentation with rudimentary shielding and filtering.>

IEEE Transactions on Applied Superconductivity•Mar 1, 1993•133 citations

Superconducting qubits meet Schrödinger’s cat

James E. Lukens

One of the many challenges facing those who would build a quantum computer is how to assemble a large enough group of qubits in a way that would permit useful computation. For this, solid state qubits have a clear advantage, and the natural order already present in a superconductor makes superconducting qubits a logical choice. The challenge for these “macroscopic” superconducting qubits is to achieve the required internal coherence between states in a single qubit in the face of interactions with the environment. Results of recent experiments at Stony Brook will be presented that demonstrate one can, in fact, produce a coherent superposition of flux states in SQUIDs (Superconducting Quantum Interference Devices). This coherence in SQUIDs is the strongest test to date of the predictions of quantum mechanics in a macroscopic system, e.g. Schrodinger’s cat.

Optical Fiber Communication Conference•Jun 13, 2001•0 citations
An integrated multipurpose setup for the automated testing of superconductor devices and circuits has been designed, implemented, and installed in the RSFQ Laboratory of the State University of New York at Stony Brook. The extendable and modular design of the setup allows a wide variety of low-frequency superconductor experiments to be carried out including those that require immediate interaction between the setup and the researcher.
A test setup bench is being implemented in the laboratory to test digital superconducting circuits under various conditions of operation. I will present in a first step the computer-controlled test environment developed to extract the main parameters of Josephson devices used in digital circuits and to test the circuits at low frequencies. Some results obtained on some Josephson junction arrays and circuits will be shown to illustrate this part. In a second step, I will review the microwave and optical signal feeds and readout that are under development in order to trigger and diagnose digital circuits at higher frequencies. Finally, a study of the expected performance of an on-chip diagnostic system aimed at discriminating different signal waveforms generated by superconducting digital circuits will be presented.
In five and a half years, the ColdFlux project under the IARPA SuperTools program pushed the boundaries of digital and analog superconductor electronic design automation (S-EDA) tools. The SuperTools program demanded significant beyond-state-of-the-art deliverables in four main areas: RTL synthesis, architectures, and verification; analog design and layout synthesis; physical design and test; and technology CAD and cell library design. Through the work of academic groups scattered over four continents, the ColdFlux effort forged into a powerful set of open-source and commercial S-EDA tools unlike any before, rivaled only by a commercial toolchain from Synopsys under the same SuperTools umbrella. We present an overview of the tools from where we started to the eventual project deliverables. These include powerful simulation and extraction engines, magnetic field and flux trapping analysis, advanced clocking methods, multi-chip interface extraction and verification, unified multi-layer design-rule compliant track blocks for automated place and route of both rapid single flux quantum (RSFQ) and adiabatic quantum-flux-parametron (AQFP) cells, models and tools for validation and test, multi-bit single flux quantum (SFQ) cells, architecture innovations for full CPU designs and more. Comprehensive cell libraries and a process design kit (PDK) were developed with the ColdFlux tools. The AQFP cell library features a logically rich collection of 80+ cells, including 3- and 5-input logic gates, signal-driving boosters, and refined RSFQ-to-AQFP interfaces, while the RSFQ library has 30+ cells. Finally, we discuss how the full toolchain enables and enhances the superconductor IC design process.
Future development of superconductor digital and mixed-signal ICs requires extensive testing with a large number of input/output (I/O) lines for applying independent bias controls, injecting test signals, and monitoring outputs of different sub-circuits. There is a growing need for a standardized test apparatus for a variety of complex superconducting chips and multichip modules (MCMs). Such a test apparatus must support many I/O lines, be easy and cost-effective to operate, and support prolonged automated testing. Existing test apparatus include liquid He cryoprobes and cryocooled custom digital-RF systems, both of which have drawbacks. Liquid He cryoprobes with universal wiring, such as 40 or 80 coaxial cables, are convenient to use. Cooled by immersion in a tank filled with liquid He, these cryoprobes allow rapid cool-down and warm-up. However, large consumption of liquid He, the cost of which has been steadily increasing worldwide, makes this solution rather expensive and wasteful. On the other hand, one can exploit the modular reconfigurability of HYPRES' digital-RF receiver product to create a testbed for different ICs. Such a system uses the smallest commercially available closed-cycle refrigerator (~1.2 kW) and has negligible operating cost. However, reconfiguration takes time and expertise since these products are specially designed with customized chip package and wiring to minimize the thermal load on the cryocooler. These low-maintenance systems are ideal for prolonged operation of a single chip, which is invaluable for superconductor electronics system developers and end-users. The integrated cryoelectronics testbed (ICE-T) combines the advantages of the liquid He cryoprobe and the cryocooled digital-RF product. By using a more powerful, commercially available, electrically powered closed-cycle refrigerator (7 kW), ICE-T alleviates the thermal constraints on wiring while maintaining very low operating cost. By separating the electrical and thermal subsystems, it maintains modularity without sacrificing the universality of the cryoprobe. A set of universal and custom electrical modules can be independently built and inserted in ICE-T. Universal inserts with 40 and 80 coaxial cables accommodate all chips with standard I/O pads like the familiar liquid He cryoprobes. Custom inserts for different classes of chips and MCMs are designed and built according to user requirements and specifications. The utility of the ICE-T was successfully demonstrated by testing a benchmark superconducting digital circuit at low frequency and an analog-to-digital converter chip clocked above 20 GHz.
Several novel circuits of the rapid single-flux-quantum (RSFQ) family of Josephson-junction digital devices have been designed, fabricated using a 2.5- mu m 1000-A/cm/sup 2/ Nb trilayer technology, and tested at low frequencies. Numerical simulation and measurements have shown that these circuits have considerably wider parameter margins, due to application of several novel design methods. The authors have also carried out an experiment to measure the rate of errors in a simple RSFQ circuit including an inverter, confluence buffer, and Josephson transmission line. Near the middle of the parameter window at 4.2 K, the error probability was definitely lower than 3*10/sup -15/ per logic operation, despite experimentation with rudimentary shielding and filtering.>
One of the many challenges facing those who would build a quantum computer is how to assemble a large enough group of qubits in a way that would permit useful computation. For this, solid state qubits have a clear advantage, and the natural order already present in a superconductor makes superconducting qubits a logical choice. The challenge for these “macroscopic” superconducting qubits is to achieve the required internal coherence between states in a single qubit in the face of interactions with the environment. Results of recent experiments at Stony Brook will be presented that demonstrate one can, in fact, produce a coherent superposition of flux states in SQUIDs (Superconducting Quantum Interference Devices). This coherence in SQUIDs is the strongest test to date of the predictions of quantum mechanics in a macroscopic system, e.g. Schrodinger’s cat.