Electron pump by a combined single-electron/field-effect- transistor structure

A silicon-based single-electron pump that operates at much higher temperatures than previous pumps is fabricated on a silicon-on-insulator substrate. The pump consists of one single-electron transistor (SET) and two ultrasmall metal-oxide-semiconductor field-effect transistors (MOSFETs). We exploit, for the operation, the extremely high off-resistance of the MOSFETs. The high resistance enables us to prevent the unwanted injection (emission) of electrons into (from) the SET nearly perfectly and to make the SET work as a pump. The operation is confirmed at 25 K at the pumping frequency of ∼1 MHz.