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.
Highlights
Manipulation of single electrons is the key to developing ultimate electronics such as single-electron-based information processors and electrical standards in metrology
Semiconductor SE pumps using localized states, such as dopants implanted in a channel[23,24,25], instead of electrically defined islands have been studied with increasing interest
The more important one is that a localized state can inherently have a large activation energy, leading to a large electron addition energy
Summary
Manipulation of single electrons is the key to developing ultimate electronics such as single-electron-based information processors and electrical standards in metrology. There have been many reports about trap levels in Si/SiO2 systems, which are detected by using several measurement techniques such as capacitance or conductance measurements[29], measurements of random telegraph signals[30], deep-level transient spectroscopy[31] and charge pumping measurements[32] From these measurements, we have acquired valuable knowledge about the trap density and capture cross section of the trap levels, but the potential for high-performance SE transfer is still uncertain. Owing to electrical controllability of the SE capture/emission rates to/from the single-trap level, we achieved high-speed SE transfer of up to 3.5 GHz with a transfer accuracy of about 10 À 3 limited by the total measurement uncertainty. The SE pump operates at a relatively high temperature (T 1⁄4 17 K) without a magnetic field because of the large activation energy of the trap level
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
