Impedance of the single-electron transistor at radio-frequencies

We experimentally characterize the impedance of a single-electron transistor (SET) at an excitation frequency comparable to the electron tunnel rate. In contrast to usual radio-frequency-SET operations, the excitation signal is applied to the gate of the device. At zero source–drain bias, the SET displays both resistive (Sisyphus resistance) and reactive (tunnelling capacitance) components to its impedance. We study the bias dependence of the complex impedance, investigating its response as the electron tunnel rate becomes large with respect to the driving frequency. The experimental data are compared with values calculated from a master equation model.