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Superconductivity and superconducting materials
Published in David Jiles, Introduction to the Electronic Properties of Materials, 2017
Along with the change in resistivity of superconductors other equally dramatic changes can occur in the electronic properties. This includes single-electron tunnelling in which electrons tunnel through a thin insulating layer between a superconducting material and a normal material known as an SIN junction. The Josephson effect [8] is a related phenomenon in which a coupled pair of electrons (a Cooper pair) passes from one superconducting region to another through a thin insulating layer known as an SIS junction. This effect can be used to construct devices which can change from one electrical state to another in very short times. This offers the opportunity for constructing logic devices and small computer circuits which operate very rapidly, with switching speeds that can be up to 10- to 100-times faster than conventional silicon devices.
Nano Superconducting Quantum Interference Device
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2020
Carmine Granata, Paolo Silvestrini, Antonio Vettoliere
The Josephson effect was predicted in 1962 by Brian Josephson. He stated that a supercurrent could tunnel through an insulating barrier separating two superconductors. A Josephson junction is schematically represented by two superconductors separated by a thin insulation barrier (Figure 10.1). If the junction is biased with a dc current, the voltage across it remains zero up to a current value called Josephson critical current I0 due to the cooper pair-tunneling through the insulation barrier. This so-called dc Josephson effect is due to the overlap of macroscopic wave functions in the barrier region (Figure 10.1).
Unconventional Designer Superconductors
Published in Grigory Tkachov, Topological Quantum Materials, 2015
The Josephson effect is a macroscopic quantum phenomenon that consists in the appearance of the electric current between two superconductors in the absence of the bias voltage. This current, called the supercurrent, is carried by Cooper pairs. The measurement of the supercurrent is one of the accessible tools to probe the symmetry of the superconducting order parameter. We may therefore ask the question of how the unconventional superconductivity and the helical ABSs in TIs manifest themselves in the Josephson effect.
Achievable Accuracy in Industrial Measurement of Dissipation Factor of Power Capacitors
Published in NCSLI Measure, 2018
The definitions in the SI system are transferred into measurable reference standards in a process called realization, which is long and difficult process, rarely performed. Quantum mechanical phenomena are instead employed to achieve very stable and reproducible representations of basic electrical units. As an example, the Josephson effect is used to link the second, Planck’s constant, and the charge of the electron, to the unit for electromotive force (voltage) [23] and doing this is one of the tasks performed by National Metrology Institutes (NMIs). To ensure international equivalence and acceptance of the established traceability, comparisons are made between NMIs.
Controlling observables in normal, hybrid and Josephson junctions
Published in Molecular Physics, 2018
K. J. Pototzky, A. Zacarias, E. K. U. Gross
In junctions with two superconducting leads, the Josephson effect causes the current to oscillate. This offers a unique way to drive the molecular vibration by tuning the DC bias such that the Josephson frequency is in resonance with the vibrational degree of freedom. This is shown in Figures 1 and 2.