A single-atom transistor is a device that can open and close an electrical circuit by the controlled and reversible repositioning of one single atom.
[1] By means of a small electrical voltage applied to a control electrode, the so-called gate electrode, a single silver atom is reversibly moved in and out of a tiny junction, in this way closing and opening an electrical contact.
[2][3][4] The single-atom transistor opens perspectives for the development of future atomic-scale logics and quantum electronics.
At the same time, the device of the Karlsruhe team of researchers marks the lower limit of miniaturization, as feature sizes smaller than one atom cannot be produced lithographically.
[5] Few atom transistors have been developed at Waseda University and at Italian CNR by Takahiro Shinada and Enrico Prati, who observed the Anderson–Mott transition[clarification needed] in miniature by employing arrays of only two, four and six individually implanted As or P atoms.