Europhys. Lett.
Volume 69, Number 3, February 2005
Page(s) 435 - 441
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 24 December 2004
Europhys. Lett., 69 (3), pp. 435-441 (2005)
DOI: 10.1209/epl/i2004-10355-6

Thermal transport in granular metals

I. S. Beloborodov1, A. V. Lopatin1, F. W. J. Hekking2, Rosario Fazio3 and V. M. Vinokur1

1  Materials Science Division, Argonne National Laboratory - Argonne, IL 60439, USA
2  Laboratoire de Physique et Modélisation des Milieux Condensés CNRS and Université Joseph Fourier - BP 166, 38042 Grenoble-cedex 9, France
3  NEST-INFM and Scuola Normale Superiore - I-56126 Pisa, Italy

received 27 August 2004; accepted in final form 19 November 2004
published online 24 December 2004

We study the electron thermal transport in granular metals at large tunnel conductance between the grains, $g_{\ab{T}}\gg 1$, and not too low a temperature, $T>g_{\ab{T}}\delta$, 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.

73.23.Hk - Coulomb blockade; single-electron tunneling.
73.22.Lp - Collective excitations.
72.15.Jf - Thermoelectric and thermomagnetic effects.

© EDP Sciences 2005