Transition from insulating to non-insulating temperature dependence of the conductivity in granular metals
Theoretische Physik III, Ruhr-Universität Bochum -
44780 Bochum, Germany
2 L. D. Landau Institute for Theoretical Physics - 117940 Moscow, Russia
Accepted: 10 April 2002
We consider interaction effects in a granular normal metal at not very low temperatures. Assuming that all weak localization effects are suppressed by the temperature we replace the initial Hamiltonian by a proper functional of phases and study the possibility for a phase transition depending on the tunneling conductance g. It is demonstrated for any dimension that, while at small g the conductivity decays with temperature exponentially, its temperature dependence is logarithmic at large g. The formulae obtained are compared with an existing experiment and a good agreement is found.
PACS: 73.23.Hk – Coulomb blockade; single-electron tunneling / 73.22.Lp – Collective excitations / 71.30.+h – Metal-insulator transitions and other electronic transitions
© EDP Sciences, 2002