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

arXiv:2405.20911

Josephson junctions, superconducting circuits, and qubit for quantum technologies

R. Citro, Claudio Guarcello, S. Pagano

Published May 31, 2024• 1 citation
arXivHTMLPDF

Abstract

In the realm of physics, a pivotal moment occurred six decades ago when Brian Josephson made a groundbreaking prediction, setting in motion a series of events that would eventually earn him the prestigious Nobel Prize eleven years later. This prediction centered around what is now known as the Josephson effect, a phenomenon with far-reaching implications. At the heart of this effect lies the Josephson junction (JJ), a device that has become a linchpin in various scientific applications. This chapter delves into the foundational principles of the Josephson effect and the remarkable properties of JJs. From their role in metrology to their application in radiation detectors, these junctions have ushered in a new era of electronics. Exploiting the unique features of superconductive devices, such as high speed, low dissipation, and dispersion, JJs find today practical implementation in the development of superconductive qubits and nanotechnology applications.

DOI
10.48550/arxiv.2405.20911

Related papers

From Macroscopic Superconductivity to Quantum Computing

Yonuk Chong

The Nobel laureates of this year have devised an experiment to observe macroscopic quantum tunneling in an electrical circuit made of superconductors. This monumental discovery has sparked numerous innovations and ultimately earned the three pioneers the Nobel prize. Afterwards, superconducting circuits play a key role in the proliferation of quantum technology in the 21st century. Especially, in the heart of the 2nd quantum revolution, quantum information technology is based on the radical development of the quantum computers. Superconducting Josephson junction devices has been the most advanced technology that has been picked up by the global tech giants in quantum computing. I will briefly review how the superconducting quantum chips and the macroscopic quantum effect had led innovation in quantum technology afterwards.

Physics and High Technology•Dec 23, 2025•0 citations

Josephson Junction, the Quantum Engine: from S.QU.I.D. Sensors to Qubits for Quantum Computers

F.M.A. Moreira

In this review of our own work, we show the physics and applications of Josephson Junction (JJ) and 2D arrays (JJA) made with this powerful quantum engine.This study is based on more than twenty articles published in more than two decades.In actual days, applications of this device go from the most sensitive sensor to measure magnetic flux, called S.QU.I.D. (from Superconducting Quantum Interference Device) to quantum bits.A unit cell of a JJ, with a cost of about a few hundred dollars allows the availability of a magnetometer with a cost of about one million dollars to a quantum computer with cost of about ten million dollars.The Josephson junction is an old quantum engine for a rising new world with incredible disruptive technological possibilities.The article is organized as follows: in section 1 we give a short introduction to the subject; section 2 describes the physics of the Josephson effect and the engineering of the Josephson junction; in section 3 we show the magnetic, transport and thermal properties of 2D-JJA; and in section 4 we show the relation between JJA and superconducting granular systems, in particular those related to High-Temperature Superconductors (HTS).

Research & Development in Material Science•May 24, 2023•1 citation

High-frequency and Digital Applications of the Josephson Effects

J. C. Gallop

We have already seen, in Chapter 2 , that the complex response of a Josephson junction to applied electromagnetic radiation forms a basis for both broad-band and heterodyne detection modes, ranging from low frequencies to the far-infrared. Greater detail of actual working devices of this type will be given in this chapter. The second topic dealt with is digital applications of squid s. This is already a significant, and may in the future become a dominant, use of low-power superconducting technology. At first sight the contents of this chapter may seem to divide into two rather disconnected areas. However, logic devices have two important characteristics in common with radiation detectors: first, both involve very high-frequency operation, since slow digital devices are of little or no practical interest. Second, both applications demand the use of well characterised and reproducible small-area junctions with similar parameters. In what follows, more details of junction fabrication methods will be given than have been discussed earlier in the book. This reflects the fact that well defined junction properties are of the utmost importance in achieving high performance in these areas. It seems paradoxical that squid s, for all their unparalleled sensitivity, will operate very satisfactorily with far from ideal Josephson junctions. This is mainly because squid s have only been used in rather low-frequency applications, for which the low resistive and reactive impedances associated with poor-quality junctions do not limit performance.

CRC Press eBooks•Oct 19, 2017•0 citations

Advances in Josephson Junction Materials and Processes Toward Practical Quantum Computing

Hyunseong Linus Kim, Gyunghyun Jang, Seungwon Jin +9 more

The Josephson junction (JJ) is the fundamental nonlinear building block of superconducting quantum technologies. Its macroscopic quantum tunneling physics underpins superconducting quantum computing, sensing, and communication, but scaling these platforms to utility-scale architectures places increasingly stringent demands on junction materials, interfaces, and fabrication. Practical quantum computing requires high reproducibility, low power consumption, tunability, a small device footprint, and resilience to noise and defects. This review surveys how advances in materials science, device characterization, and nanofabrication are addressing these challenges and redefining the figures of merit for next-generation JJs. This review also examines the evolution of fabrication strategies, from conventional multi-angle evaporation to foundry-compatible superconducting processes and the integration of emerging junction materials. Progress along these directions will determine how rapidly JJs move from laboratory-scale components to the foundation of industrial-scale quantum processors.

arXiv:2505.12724•Advanced Science•Oct 28, 2026•0 citations

Evidence for Superconducting Artificial Atom

Yong‐Joo Doh

This year’s Nobel Prize in Physics was awarded for the experimental demonstration of macroscopic quantum tunneling and energy quantization of the phase particle defined in a Josephson junction. This groundbreaking work extended quantum mechanics beyond microscopic systems into the macroscopic realm. By revealing that Josephson junctions could function as superconducting artificial atoms, the discovery enabled researchers to engineer and control quantum states with unprecedented precision, thereby providing a crucial foundation for the subsequent development of superconducting quantum computers.

Physics and High Technology•Dec 23, 2025•0 citations

Josephson-junction logic and memory circuits

Gloria B. Lubkin

The superconducting tunnel effect predicted by Brian Josephson in 1962 is looking increasingly promising for another very practical application—as logic and memory circuits for computers. Josephson-junction circuits are capable of high switching speeds (50–100 picosec have already been obtained). And because such circuits operate at voltages comparable to the superconducting energy gap, the heat generated is typically microwatts, thousands of times lower than high-speed transistor circuits. The diminished heat-removal problem allows one to pack the Josephson circuits much closer than semiconductor circuits. Once high switching speeds are achieved, this packability becomes extremely important because then the major limitation on computer speed is how fast the electrical signal takes to move from one circuit to another.

Physics Today•Jun 1, 1978•0 citations
In the realm of physics, a pivotal moment occurred six decades ago when Brian Josephson made a groundbreaking prediction, setting in motion a series of events that would eventually earn him the prestigious Nobel Prize eleven years later. This prediction centered around what is now known as the Josephson effect, a phenomenon with far-reaching implications. At the heart of this effect lies the Josephson junction (JJ), a device that has become a linchpin in various scientific applications. This chapter delves into the foundational principles of the Josephson effect and the remarkable properties of JJs. From their role in metrology to their application in radiation detectors, these junctions have ushered in a new era of electronics. Exploiting the unique features of superconductive devices, such as high speed, low dissipation, and dispersion, JJs find today practical implementation in the development of superconductive qubits and nanotechnology applications.
The Nobel laureates of this year have devised an experiment to observe macroscopic quantum tunneling in an electrical circuit made of superconductors. This monumental discovery has sparked numerous innovations and ultimately earned the three pioneers the Nobel prize. Afterwards, superconducting circuits play a key role in the proliferation of quantum technology in the 21st century. Especially, in the heart of the 2nd quantum revolution, quantum information technology is based on the radical development of the quantum computers. Superconducting Josephson junction devices has been the most advanced technology that has been picked up by the global tech giants in quantum computing. I will briefly review how the superconducting quantum chips and the macroscopic quantum effect had led innovation in quantum technology afterwards.
In this review of our own work, we show the physics and applications of Josephson Junction (JJ) and 2D arrays (JJA) made with this powerful quantum engine.This study is based on more than twenty articles published in more than two decades.In actual days, applications of this device go from the most sensitive sensor to measure magnetic flux, called S.QU.I.D. (from Superconducting Quantum Interference Device) to quantum bits.A unit cell of a JJ, with a cost of about a few hundred dollars allows the availability of a magnetometer with a cost of about one million dollars to a quantum computer with cost of about ten million dollars.The Josephson junction is an old quantum engine for a rising new world with incredible disruptive technological possibilities.The article is organized as follows: in section 1 we give a short introduction to the subject; section 2 describes the physics of the Josephson effect and the engineering of the Josephson junction; in section 3 we show the magnetic, transport and thermal properties of 2D-JJA; and in section 4 we show the relation between JJA and superconducting granular systems, in particular those related to High-Temperature Superconductors (HTS).
We have already seen, in Chapter 2 , that the complex response of a Josephson junction to applied electromagnetic radiation forms a basis for both broad-band and heterodyne detection modes, ranging from low frequencies to the far-infrared. Greater detail of actual working devices of this type will be given in this chapter. The second topic dealt with is digital applications of squid s. This is already a significant, and may in the future become a dominant, use of low-power superconducting technology. At first sight the contents of this chapter may seem to divide into two rather disconnected areas. However, logic devices have two important characteristics in common with radiation detectors: first, both involve very high-frequency operation, since slow digital devices are of little or no practical interest. Second, both applications demand the use of well characterised and reproducible small-area junctions with similar parameters. In what follows, more details of junction fabrication methods will be given than have been discussed earlier in the book. This reflects the fact that well defined junction properties are of the utmost importance in achieving high performance in these areas. It seems paradoxical that squid s, for all their unparalleled sensitivity, will operate very satisfactorily with far from ideal Josephson junctions. This is mainly because squid s have only been used in rather low-frequency applications, for which the low resistive and reactive impedances associated with poor-quality junctions do not limit performance.
The Josephson junction (JJ) is the fundamental nonlinear building block of superconducting quantum technologies. Its macroscopic quantum tunneling physics underpins superconducting quantum computing, sensing, and communication, but scaling these platforms to utility-scale architectures places increasingly stringent demands on junction materials, interfaces, and fabrication. Practical quantum computing requires high reproducibility, low power consumption, tunability, a small device footprint, and resilience to noise and defects. This review surveys how advances in materials science, device characterization, and nanofabrication are addressing these challenges and redefining the figures of merit for next-generation JJs. This review also examines the evolution of fabrication strategies, from conventional multi-angle evaporation to foundry-compatible superconducting processes and the integration of emerging junction materials. Progress along these directions will determine how rapidly JJs move from laboratory-scale components to the foundation of industrial-scale quantum processors.
This year’s Nobel Prize in Physics was awarded for the experimental demonstration of macroscopic quantum tunneling and energy quantization of the phase particle defined in a Josephson junction. This groundbreaking work extended quantum mechanics beyond microscopic systems into the macroscopic realm. By revealing that Josephson junctions could function as superconducting artificial atoms, the discovery enabled researchers to engineer and control quantum states with unprecedented precision, thereby providing a crucial foundation for the subsequent development of superconducting quantum computers.
The superconducting tunnel effect predicted by Brian Josephson in 1962 is looking increasingly promising for another very practical application—as logic and memory circuits for computers. Josephson-junction circuits are capable of high switching speeds (50–100 picosec have already been obtained). And because such circuits operate at voltages comparable to the superconducting energy gap, the heat generated is typically microwatts, thousands of times lower than high-speed transistor circuits. The diminished heat-removal problem allows one to pack the Josephson circuits much closer than semiconductor circuits. Once high switching speeds are achieved, this packability becomes extremely important because then the major limitation on computer speed is how fast the electrical signal takes to move from one circuit to another.