Single-electron transistors

Single-electron transistors (SET's) are often discussed as elements of nanometer scale electronic circuits because they can be made very small and they can detect the motion of individual electrons. However, SET's have low voltage gain, high output impedances, and are sensitive to random background charges. This makes it unlikely that single-electron transistors would ever replace field-effect transistors (FET's) in applications where large voltage gain or low output impedance is necessary. The most promising applications for SET's are charge-sensing applications such as the readout of few electron memories, the readout of charge-coupled devices, and precision charge measurements in metrology.