Evidence for universal conductance correction in a tunable strongly coupled nanogranular metal
Abstract
We present temperature-dependent conductivity data obtained on a sample set of nanogranular Pt-C with finely tuned inter-grain tunnel coupling strength g. For samples in the strong-coupling regime g > g_C, characterized by a finite conductivity for T -> 0, we find a logarithmic behavior at elevated temperatures and a crossover to a sqrt(T)-behavior at low temperatures over a wide range of coupling strengths g_C = 0.25 < g <= 3. The experimental observation for g > 1 is in very good agreement with recent theoretical findings on ordered granular metals in three spatial dimensions. The results indicate a validity of the predicted universal conductivity behavior that goes beyond the immediate range of the approach used in the theoretical derivation.
Keywords
Cite
@article{arxiv.1108.2961,
title = {Evidence for universal conductance correction in a tunable strongly coupled nanogranular metal},
author = {Roland Sachser and Fabrizio Porrati and Christian H. Schwalb and Michael Huth},
journal= {arXiv preprint arXiv:1108.2961},
year = {2015}
}