We suggest to use `fluctuation spectroscopy' as a method to detect granularity in a disordered metal close to a superconducting transition. We show that with lowering temperature T the resistance R(T) of a system of relatively large grains initially grows due to the fluctuation suppression of the one-electron tunneling but decreases with further lowering T due to the coherent charge transfer of the fluctuation Cooper pairs. Under certain conditions, such a maximum in R(T) turns out to be sensitive to weak magnetic fields due to a novel Maki -- Thompson type mechanism.
@article{arxiv.0707.4237,
title = {Fluctuation spectroscopy of granularity in superconducting structures},
author = {I. V. Lerner and A. A. Varlamov and V. M. Vinokur},
journal= {arXiv preprint arXiv:0707.4237},
year = {2008}
}
Comments
A final version, as published; the introduction and summary are considerably revised