The paper is published in Philosophical Magazine B 81(9), 997-1009 (2001).

Conduction in Granular Metals by Hopping via Virtual States

I.P. Zvyagin, R. Keiper

It is shown that the conductivity of granular metals on the insulating side of the metal--insulator transition can be essentially determined by inter-grain tunneling via virtual localized states of intermediate grains. This mechanism gives rise to conductivity temperature dependence of the form ln(sigma)=const-(T0/T)x, where x is about 0.4, and to a large enhancement of the conductivity.

Other works on theory of semiconductors