STRONG ELECTRON-TUNNELING THROUGH A SMALL METALLIC GRAIN

Electron tunneling through mesoscopic metallic grains can be treated p erturbatively only under the conduction that the tunnel junction condu ctances are sufficiently small. If that is not the case, fluctuations of the grain charge become strong. As a result (i) the contributions o f all-including high energy-charge states become important, and (ii) t he excited charge states become broadened and essentially overlap. At the same time, the grain charge remains discrete and the system conduc tance e-periodically depends on the gate charge. We develop a non-pert urbative approach which accounts for all these features and calculate the temperature-dependent conductance of the system in the strong tunn eling regime at different values of the gate charge. (C) 1996 American Institute of Physics.