Single-electron inverter

A single-electron inverter was fabricated that switches from a high output to a low output when a fraction of an electron is added to the input. For t he proper operation of the inverter, the two single-electron transistors th at make up the inverter must exhibit voltage gain. Voltage gain was achieve d by fabricating a combination of parallel-plate gate capacitors and small tunnel junctions in a two-layer circuit. Voltage gain of 2.6 was attained a t 25 mK and remained larger than one for temperatures up to 140 mK. The tem perature dependence of the gain agrees with the orthodox theory of single-e lectron tunneling. (C) 2001 American Institute of Physics.