Dual Function of Single Electron Transistor Coupled with Double Quantum Dot: Gating and Charge Sensing

We demonstrate gating and charge sensing functions of a lithographically defined single electron transistor (SET). The electrochemical potential of the SET is modulated by applying a voltage to both the source and drain electrodes. The SET integrated with a double quantum dot (DQD) works as a gate electrode for the DQD. Charge transitions in the DQD are detected by the SET through its charge sensing function. This dual function of the SET is useful for saving space in crowded devices with many gates and charge sensors, toward the integration of multiqubits for quantum computation. (C) 2013 The Japan Society of Applied Physics