Mesoscopic tunnel junctions

Amman M, Wilkins R, Ben-Jacob E et al (1991) Analytic solution for the current-voltage characteristic of two mesoscopic tunnel junctions coupled in series. Phys Rev B 43 1146-1149... 

One dimensional arrays of mesoscopic tunnel junctions, built up from clusters, have been treated theoretically (see also Section 4.4.3.2). There are different means of arranging clusters in one dimension, e.g. inclusion into ID channel structures, connection to rod-like molecules, such as DNA strands,or deposition on to preformed substrates. The preparation techniques will cover a broad field ranging from self-assembly or LB techniques, through nanoreactor synthesis, up to electrodeposition. 

To analyze the effect of disorder, an exact analytical solution in terms of Green s function (GF) for the potential distribution in a finite 1-D array was shown to be appropriate (Figure 5.39) [53, 54]. The GF approach allows the formulation of the so-called partial solitary problem of small mesoscopic tunnel junctions, similar to the problem of the behavior of an electron in 1-D tight binding and in a set of random delta-function models. 

In this paper, we report measurements of the low temperature differential resistance of mesoscopic FS junctions. We observe asymmetries in the differential resistance even in the absence of an external magnetic field. These asymmetries are associated with spin-polarized tunneling into the superconductor, with the splitting of the quasi-particle density of states in the superconductor arising from the magnetic field generated by the ferromagnetic elements. 

Summary. We discuss how threshold detectors can be used for a direct measurement of the full counting statistics (FCS) of current fluctuations and how to implement Josephson junctions in this respect. We propose a scheme to characterize the full counting statistics from the current dependence of the escape rate measured. We illustrate the scheme with explicit results for tunnel, diffusive and quasi-ballistic mesoscopic conductors. 

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