Strong tunneling in the single-electron transistor

We have investigated the suppression of single-electron charging effects in metallic single-electron transistors when the conductance of the tunnel junctions becomes larger than the conductance quantum e(2)/h. We find that the Coulomb blockade of the conductance is progressively shifted at lower temperatures. The experimental results agree quantitatively with the available 1/T expansion at high temperature, and qualitatively with the predictions of an effective two-state model at low temperature, which predicts at T = 0 a blockade of conductance for all gate voltages.