Single-electron pumping in single-common-gate quadruple-dot devices with asymmetric gate capacitances

Abstract

Single-common-gate quadruple-dot single-electron devices with asymmetric gate capacitances (Cg) can transfer a single electron to a negative-biased electrode by alternating only one gate voltage. The pumping is possible for non-monotonic Cg distributions such as saw-toothed and various random Cg distributions, though the Cg distributions of the previously reported common-gate triple-dot pumping devices are limited to monotonic ones. The maximum absolute value of negative-biasing voltage against which a single electron can be transferred is 0.2181·e/Cj, where e is the elementary charge and Cj is the junction capacitance. This is 2.7 times larger than the largest one in common-gate triple-dot pumping devices with a monotonic Cg distribution.