Josephson Junction

Extracted Attributes

• Nature

  Macroscopic quantum phenomenon/device

• Components

  Two superconductors, weak link

• Key Property

  Exhibits precise relationships between voltage and frequency

• Predicted by

  Brian Josephson

• Core Principle

  Josephson effect

• Prediction Date

  1962

• Weak Link Types

  Superconductor-Insulator-Superconductor (S-I-S), Superconductor-Normal metal-Superconductor (S-N-S), Superconductor-constriction-Superconductor (S-c-S)

• Standard Application

  NIST standard for one volt

• NIST Standard Junction Count

  20,208 Josephson junctions in series

Timeline

• Brian Josephson predicts the mathematical relationships for the current and voltage across the weak link, describing the Josephson effect. (Source: Summary, Wikipedia)

  1962

• Brian Josephson submits his paper 'Possible new effects in superconductive tunnelling' to Physics Letters. (Source: Web Search)

  1962-06

• Philip W. Anderson and John Rowell submit the first paper to Physical Review Letters claiming experimental observation of the Josephson effect. (Source: Web Search)

  1963-01

• John Martinis conducts research, detailed in his landmark paper, demonstrating for the first time that an electrical circuit built with Superconductors and a Josephson Junction exhibits quantum phenomena like Quantum Tunneling, laying the experimental foundation for Quantum Computing. (Source: Related Documents)

  1985

• John Martinis's team at Google achieves Quantum Supremacy, utilizing superconducting qubits based on Josephson junctions. (Source: Summary, Related Documents)

  2019

• John Martinis is recognized as the 2025 winner of the Nobel Prize in Physics for his work, which includes pioneering research with Josephson junctions. (Source: Related Documents)

  2025

Josephson effect

In physics, the Josephson effect is a phenomenon that occurs when two superconductors are placed in proximity, with some barrier or restriction between them. The effect is named after the British physicist Brian Josephson, who predicted in 1962 the mathematical relationships for the current and voltage across the weak link. It is an example of a macroscopic quantum phenomenon, where the effects of quantum mechanics are observable at ordinary, rather than atomic, scale. The Josephson effect has many practical applications because it exhibits a precise relationship between different physical measures, such as voltage and frequency, facilitating highly accurate measurements. The Josephson effect produces a current, known as a supercurrent, that flows continuously without any voltage applied, across a device known as a Josephson junction (JJ). This consists of two or more superconductors coupled by a weak link. The weak link can be a thin insulating barrier (known as a superconductor–insulator–superconductor junction, or S-I-S), a short section of non-superconducting metal (S-N-S), or a physical constriction that weakens the superconductivity at the point of contact (S-c-S). Josephson junctions have important applications in quantum-mechanical circuits, such as SQUIDs, superconducting qubits, and RSFQ digital electronics. The NIST standard for one volt is achieved by an array of 20,208 Josephson junctions in series.

Web Search Results

• What are Josephson junctions? How do they work?

  At this "critical temperature," the metal goes from what is known as the normal state, where it has electrical resistance, to the superconducting state, where there is essentially no resistance to the flow of direct electrical current. These cookies may be set through our site by ourselves. These cookies collect information for analytics and to personalize your experience with targeted ads. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance. These cookies are set by a range of social media services that we have added to the site to enable you to share our content with your friends and networks.

• Josephson effect - Wikipedia

  The Josephson effect produces a current, known as a supercurrent, that flows continuously without any voltage applied, across a device known as a **Josephson junction** (JJ).*[clarification needed*] This consists of two or more superconductors coupled by a weak link. Josephson junctions have important applications in quantum-mechanical circuits, such as SQUIDs, superconducting qubits, and RSFQ digital electronics. Josephson then submitted "Possible new effects in superconductive tunnelling" to *Physics Letters* in June 1962. In January 1963, Anderson and his Bell Labs colleague John Rowell submitted the first paper to *Physical Review Letters* to claim the experimental observation of Josephson's effect "Probable Observation of the Josephson Superconducting Tunneling Effect". *Physics and Applications of the Josephson Effect*.

• How Josephson Junctions Power Quantum Computing [Full Guide]

  # How Josephson Junctions Power Quantum Computing [Full Guide] 2025.04.29 · Blog josephson junction quantum computing * Josephson junctions enable ***superconducting qubits***, which are critical for quantum computation. ## Understanding Josephson Junctions in Quantum Computing ## How Josephson Junctions Work in Quantum Computing In quantum computing, Josephson junctions are used to create qubits through superconducting circuits. The Josephson junction's ability to control and manipulate these quantum states enables the construction of high-fidelity qubits, which are essential for the performance of quantum computers. ## Applications of Josephson Junctions in Quantum Computing ## Josephson Junctions in Quantum Computers and Future Developments Josephson junctions are indispensable in the development of quantum computing and qubits. What Is Quantum Computing? quantum computer

• [PDF] Some applications of the Josephson effect. - GovInfo

  B. Sullivan Cryogenics Division Institute for Basic Standards National Bureau of Standards Boulder, Colorado 80302 Final Report on Interagency Order NASA-C-7756-B National Aeronautics and Space Administration Lewis Research Center Cleveland, Ohio NBS Technical Notes are designed to supplement the Bureau's regular publications program. Current versus voltage characteristic of a thin film Josephson junction connected to a circuit with a resonance at frequency / = 2eV/h 46 Figure 12. Sullivan We describe techniques for fabricating permanent Josephson junctions between thin films of niobium and lead, and for absolute noise thermometry at very low temperatures using the Josephson effect. Josephson, Possible new effects in superconductive tunneling, Physics Letters l_f 251-253 (1962).

• [PDF] Superconducting Qubits and the Physics of Josephson Junctions

  Section 7 expands upon this theory and describes quasiparticle excitations as transitions from the ground to excited bound states from Superconducting Qubits and the Physics of Josephson Junctions 3 φ L φ R V I J Figure 1. Because this excited state initially has energy less than ∆, the state remains bound until the phase Superconducting Qubits and the Physics of Josephson Junctions 21 x V ( x ) R e { k } Im{k } E / ∆ R e { δ } Im { δ } (a ) ( b) Figure 11. (87) Superconducting Qubits and the Physics of Josephson Junctions 22 (a ) ∆ /e V δ 2π 0 Ι J 0 0 (b ) (c ) ) / 2 /( h e I ∆ j Figure 12.