Towards Single-Electron Metrology

Abstract

We review the status of the understanding of single-electron transport (SET) devices with respect to their applicability in metrology. Their envisioned role as the basis of a high-precision electrical standard is outlined and is discussed in the context of other standards. The operation principles of single electron transistors, turnstiles and pumps are explained and the fundamental limits of these devices are discussed in detail. We describe the various physical mechanisms that influence the device uncertainty and review the analytical and numerical methods needed to calculate the intrinsic uncertainty and to optimise the fabrication and operation parameters. Recent experimental results are evaluated and compared with theoretical predictions. Although there are discrepancies between theory and experiments, the intrinsic uncertainty is already small enough to start preparing for the first SET-based metrological applications. DFM-98-R27Towards single-electron metrology 2

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

“…Using this principle Keller et al [17] achieved an uncertainty of 15 × 10 −9 with f up to a few MHz determined by electron counting. A comprehensive review of single-electron metrology with fixedbarrier single-electron transistors has been compiled by Flensberg et al [4] in 1999 (see also Likharev [18]). …”

Noise measurement of a quantized charge pump

“…The current noise is monitored by a fast-Fourier-transform analyzer. The measurements are carried out in a 3 He system at a temperature of 0.4 K.…”

Operation of a three-junction single-electron pump with on-chip resistors

“…Due to this property, the pump operating during a certain time interval can be utilized as, e.g., an accurate source of charge for the standard of capacitance 4 or can be exploited for a number of fundamental metrological experiments. 5 In the simplest pump (Nϭ3), the dominant factor limiting the pumping accuracy at low T is the process of electron cotunneling. 6 In this uncontrolled process, the charge is transferred by simultaneous tunneling in several junctions in one quantum event.…”