A new single electron transistor

The authors propose and demonstrate a novel single-electron transistor (SET) where the drain current is controlled by a single electron. This SET is similar to a GaAs-AlGaAs heterostructure modulation-doped FET, except that it has a split gate which electrostatically squeezes a 2-D channel into a 1-D channel, and it also has a nanoscale metal bar inside the gate gap to form a potential barrier in the 1-D channel. At certain gate voltages, a single electron can be 'stopped' inside the 1-D channel by the potential barrier, and due to Coulomb repulsion this electron 'blocks' the current flow from the source of the FET to the drain (Coulomb blockade). Therefore, the drain current of the SET will oscillate with the gate voltage, giving strong negative differential resistances, instead of being a linear function of gate voltage, as in a conventional FET operated in the linear regime.