Gigahertz single-trap electron pumps in silicon.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 25284206.
- Also identified by DOI 10.1038/ncomms6038 and PMC identifier 4205845.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Manipulation of single electrons is the key to developing ultimate electronics such as single-electron-based information processors and electrical standards in metrology. Especially, high-frequency and high-accuracy single-electron pumps are essential to realize practical current standards. While electrically defined quantum dots are widely used to build single-electron pumps, a localized state in semiconductors is also a potential candidate for accurate pumps because it can have a large activation energy for the captured electron. However, the transfer mechanism of such localized-state-mediated single-electron pumps for high-accuracy operation at a high frequency has not been well examined. Here we demonstrate a single-electron pump using a single-trap level with an activation energy of a few ten millielectron volts in Si nanotransistors. By means of gate control of capture and emission rates, the pump operates at a frequency of 3 GHz with an accuracy of better than 10(-3) at 17 K, indicating that an electric field at the trap level lowers the capture and emission time to less than 25 ps.