Strong election tunneling thiough a small metallic grain
Golubev D.S., Zaikin A.D.
Electron tunneling through mesoscopic metallic grains can be treated pertur-batively only provided the tunnel junction conductances are sufficiently small. If it is not the case, fluctuations of the grain charge become strong. As a result (j) contributions of all — including high energy — charge states become important and (ii) excited charge states become broadened and essentially overlap. At the same time the grain charge remains discrete and the system conductance e-periodically depends on the gate charge. We develop a nonperturbative approach which accounts for all these features and calculate the temperature dependent conductance of the system in the strong tunneling regime at different values of the gate charge. PACS: 73.40.-c