Gigahertz single-trap electron pumps in silicon

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.

Non-adiabatic quantized charge pumping with tunable-barrier quantum dots: a review of current progress

“…Pumping through a single donor atom at a much higher rate of 1 GHz was demonstrated by Tettamanzi et al [73] at T = 4.2 K. Yamahata et al argue in [74] that the use of charge trap levels as the quantization-defining localized states may lead to higher operation frequencies and precision. By electrically controlling the capture and emission rates to and from a trap level the authors of [74] have demonstrated quantized pumping up to the frequency of 3.5 GHz with a transfer accuracy of about 10 −3 , limited by their measurement uncertainty. The device operated at a temperature of T = 17 K.…”

“…Universal, analytic results are possible only in special limits, of which a particularly useful one is the statistics of charge capture [52,108,111,124,[145][146][147] (see also an analytic solution for time-limited emission with constant rates in [74,96,148,149]). To model charge capture in a QD by a closing tunable barrier, we follow [147] and consider a close-enough-to-equilibrium initial state of the dot at t = t 0 , when it is well connected to the source lead.…”

“…Additional steps at the top of Figure 12(b), such as the one corresponding to case D, are due to emission-rate separation between different charge states at stage (iv). Identification of plateaux edges and their connection to specific phases of a non-adiabatic pumping cycle can be done along similar lines for other choices of control voltages, see [52,68,73,74,148]. Deliberately tuning the pump into emission-or loading-limited regimes has been used to explore voltage-and temperature-dependence of the relevant charge exchange rates [10,74,148].…”

Stability of Single Electron Devices: Charge Offset Drift

“…This ability to manipulate individual electrons leads to several applications. Metrologists have pursued electron-counting standards for capacitance [1,2] and current [3][4][5][6][7][8][9][10] since the realization of SEDs. Others have worked to perform logic or memory applications with SEDs because of the prospect for doing so at very low power [11][12][13][14].…”

Изучение Профиля Распределения Железа, Имплантированного В Кремний

“…Проектируются и создаются ключе-вые элементы микросхем, в которых активный элемент реализуется несколькими или даже одним атомом. Были продемонстрированы прототипы одноатомных одноэлек-тронных устройств: квантового бита [5][6][7], квантово-го логического вентиля [8], устройств для квантовой метрологии [9,10], сверхчувствительных зарядовых сен-соров для биологических применений [11]. Точность моделирования распределения внедряемой примеси по глубине будет в значительной мере определять рабочие характеристики элемента микросхемы.…”