The push to develop single-electron devices has gotten a shot in the arm from two recent contributions from Japan.
Most existing SETs work only at extremely low temperatures.
Toshiba's SET operation depends on manipulating an electron's behavior under what is known as the Coulomb Blockade Effect. This phenomenon relies on the simple principle that two electrons cannot enter one quantum hole. If one electron is in one quantum hole, the next electron cannot enter because of mutual repulsion. But when a quantum dot confining an electron becomes small enough, the electron's repulsive energy becomes strong enough to demonstrate SET operation at room temperature. Peaks and troughs Toshiba engineers used a chemical-treatment process instead of a lithographic approach to create the small quantum dots.