Thermal transport in granular metals

I. S. Beloborodov, A. V. Lopatin, F. W. J. Hekking, Rosario Fazio, V. M. Vinokur

Published 2004-02-06, updated 2005-02-01Version 2

We study the electron thermal transport in granular metals at large tunnel conductance between the grains, $g_T \gg 1$ and not too low a temperature $T > g_T\delta$, where $\delta$ is the mean energy level spacing for a single grain. Taking into account the electron-electron interaction effects we calculate the thermal conductivity and show that the Wiedemann-Franz law is violated for granular metals. We find that interaction effects suppress the thermal conductivity less than the electrical conductivity.