Superconducting wires transport

It is clear that the existence of the critical field also implies the existence of a critical transport electrical current in a superconducting wire, i.e., that current Ic, which produces the critical field Hc at the surface of the wire. For example, in a cylindrical wire of radius r, I, = 1rHc. This result is called the Silsbee ntle. 

In the Andreev interferometers (see Fig. 1), the phase relations between the electron and hole wavefunctions in the normal wire can be controlled by the magnetic flux enclosed by a superconducting loop, which results in the periodic dependence of transport characteristics of the interferometer on the superconducting phase difference across the SNS junction. Initially, the oscillations of the conductance were investigated both experimentally (see a review in Ref. [11]) and theoretically [12], and, more recently, the oscillations in the current noise were reported [10]. 

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