Single-Electron Pump Based on Charging Effects

TLDR

We have designed and operated a device consisting of three nanoscale tunnel junctions biased below the Coulomb gap. The device uses phase‑shifted rf voltages at frequency f applied to two gates to pump one electron per cycle through the three‑junction structure. This is shown experimentally by plateaus in the current–voltage characteristic at I = ± ef, with the current sign determined by the rf phase rather than the bias polarity.

Abstract

We have designed and operated a device consisting of three nanoscale tunnel junctions biased below the Coulomb gap. Phase shifted r.f. voltages of frequency f applied to two gates "pump" one electron per cycle through the device. This is shown experimentally by plateaus in the current-voltage characteristic at I = ± ef, the sign of the current depending on the relative phase of the r.f. voltages and not on the sign of the bias voltage.