Distribution functions and current-correlations in normal-metal--superconductor hetero-structures
Abstract
We introduce electron-like and hole-like distribution functions, which determine the currents and the fluctuation spectra of the currents measured at a normal-conductor--superconductor hetero-structure. These distribution functions are expressed with the help of newly defined partial densities of states for hetero-structures. Voltage measurements using a weakly coupled contact on such a structure show the absence of a contact resistance to the superconducting reservoir and illustrate how the interface to the superconductor acts as an Andreev mirror. We also discuss the current-current correlations measured at two normal contacts and argue that the appearance of positive correlations is a purely mesoscopic effect, which vanishes in the limit of a large number of channels and in the average over an ensemble.
Cite
@article{arxiv.cond-mat/9908469,
title = {Distribution functions and current-correlations in normal-metal--superconductor hetero-structures},
author = {Thomas Gramespacher and Markus Buttiker},
journal= {arXiv preprint arXiv:cond-mat/9908469},
year = {2009}
}
Comments
8 pages REVTeX, 1 figure