Superconducting Fluctuations in Granular Metals with a Large Coupling Between the Grains

Abstract

We study the fluctuation conductivity of superconducting granular metals at low temperatures and strong magnetic field destroying the Cooper pairs. Explicit calculations are performed for larger values of the coupling between the grains than those considered in previous works. We show that in a broad region of the coupling constants the superconducting fluctuations still significantly reduce the conductivity leading to a negative magnetoresistance.