Nanoampere charge pump by single-electron ratchet using silicon nanowire metal-oxide-semiconductor field-effect transistor

Nanoampere single-electron pumping is presented at $20K$ using a single-electron ratchet comprising silicon nanowire metal-oxide-semiconductor field-effect transistors. The ratchet features an asymmetric potential with a pocket that captures single electrons from the source and ejects them to the drain. Directional single-electron transfer is achieved by applying one ac signal with the frequency up to $2.3GHz$⁠. We find anomalous shapes of current steps which can be ascribed to nonadiabatic electron capture.