Josephson junctions, types

Fig. 10.13. I-V curve for 45°/[001] tilt grain boundary in YBCO, showing Josephson junction type behavior [10.58].

Thin-fiim technology has also played an important role in developing Josephson superconducting devices, which offer outstanding advantages in constructing ultrahigh-speed computers, These are tunnel-junction type devices. 

To conclude, we proved that Josephson junctions can be used as threshold detectors for non-Gaussian noise produced by coherent conductors. Our theoretical results facilitate a new type of electric noise measurement direct measurement of full counting statistics of the transferred charge. 

Anomalous diffusion was first investigated in a one-dimensional chaotic map to describe enhanced diffusion in Josephson junctions [21], and it is observed in many systems both numerically [16,18,22-24] and experimentally [25], Anomalous diffusion is also observed in Hamiltonian dynamical systems. It is explained as due to power-type distribution functions [22,26,27] of trapping and untrapping times of the orbit in the self-similar hierarchy of cylindrical cantori [28]. 

Josephson junction A type of electronic circuit capable of switching at very high speeds when operated at temperatures approaching absolute zero. Composed of two superconductors that are separated by a thin nonsuperconducting layer in which electrons can cross through the insulating barrier, it was discovered by... 

Before analyzing (4), we mention some typical parameter values for Josephson junctions. The critical current is typically in the range I I /zA- 1 mA, and a typical voltage is I R 1 mV. Since le/h 4,83 x 10 " Hz/V, a typical frequency is on the orderof lO" Hz. Finally, a typical length scale for Josephson junctions is around 1 (im, but this depends on the geometry and the type of coupling used. 

We will describe two different types of Josephson junctions (i) The Anderson-Dayem bridges, the behavior of which can be interpreted very nicely in terms of dissipative structures, but for which the theoretical description is not so simple. 

Fig. 13.17. Edge-type multilayer Josephson junction as developed by Faley et al. [13.12, 13.13].

The microstructure of YBa2Cu30y thin films and related heterostructures, which are the basis for several types of edge-based Josephson junction were investigated by high-resolution transmission electron microscopy. The results show that the microstructure, interfaces, grain boundaries and defect configurations in these films are strongly influenced by the substrate and the often complex structure of the film surfaces on which the subsequent layers are deposited. 

A Junction of this type is called a Josephson junction two or more Junctions Joined by superconducting paths form a Josephson Interferometer. Such Junctions can be used in measuring fundamental constants, in defining a voltage standard, and in the highly accurate measurement of magnetic fields. 

The first kind of approaches is to investigate the diiferential conductance (d//dF) spectrum with various geometries in SIN or SIS junctions. The other type is to measure the dependence of the Josephson critical current J), as a function of plied magnetic field. 

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