NIST is developing a new electrical current standard based on single electron devices in silicon. The standard would produce a current of about 10 nA from 100 single electron devices operating in parallel, with a relative error rate below 10-8. The devices manipulate and trap a single electron in a quantum dot using voltages applied to electrostatically controlled tunnel barriers.
The current is produced by cycling the voltages to sequentially pump one electron at a time through the device at a frequency f, resulting in a current I = ef. When operated in parallel, the current is multiplied by the number of devices. NIST is collaborating closely on this work and the devices used for the current standard are similar to those used for quantum coherent experiments.
Two different architectures are being developed for the single electron devices with integrated charge sensors – one using polycrystalline silicon gates on a bulk wafer, and the other utilizing mesa-etched silicon-on-insulator (SOI) wafers with polycrystalline silicon gates.
Source: https://www.nist.gov/programs-projects/silicon-based-single-electron-current-standards
Keywords: Electron, Current standard, Frequency, Devices, Metrology
