Transporting single electrons

Article By:

Janssen, Jan-Theodoor Time, Quantum and Electromagnetics Division, National Physical Laboratory, Teddington, Middlesex, United Kingdom.

Last reviewed:2003

DOI:https://doi.org/10.1036/1097-8542.YB031535

The manipulation of individual electrons has become possible as a result of the steady advances in nanolithography over the last 10 years. Today the transport of single electrons can be routinely achieved at very low temperatures in specially designed circuits having critical dimensions of several hundred nanometers or less. In a single-electron-transport device, electrons can be clocked through a circuit at a certain frequency. The resulting electrical current I_S through the circuit is the electron charge e times the clock frequency f. If the frequency is locked to a standard, a fundamental or quantum standard of current is generated. A quantum standard of current will be of great interest to the metrological community concerned with the derivation of electrical units from basic physical laws and dissemination of these for commercial calibrations. This is because a quantum standard of current would complete the “metrological triangle” of connections between the already-existing electrical quantum standards of resistance and voltage, which are based on the quantum Hall effect and the Josephson effect respectively, and the new quantum standard of current.

The content above is only an excerpt.