The Single-Atom Transistor: Quantum Electronics at Room Temperature

An atomic-scale quantum conductance switch is demonstrated which allows to open and close an electrical circuit by the controlled and reproducible reconfiguration of silver atoms within an atomic-scale junction (Fig. 1). The only movable parts of the switch are the contacting atoms. The atomic switch is entirely controlled by an external voltage applied to an independent third gate electrode. Controlled switching was performed between a quantized, electrically conducting "on-state" exhibiting a conductance of G(0) = 2e(2)/h (approximate to 1/12.9k Omega) or preselectable multiples of this value and an insulating "off-state". The device which reproducibly operates at room temperature, opens fascinating perspectives towards quantum electronics and logics on the atomic scale. Even an integrated circuit consisting of atomic-scale transistors was shown [1].