Related papers: On the quantization accuracy of the acoustoelectri…
We report on high-accuracy measurements of quantized current, sourced by a tunable-barrier single-electron pump at frequencies $f$ up to $1$ GHz. The measurements were performed with a new picoammeter instrument, traceable to the Josephson…
Fluctuations in the acoustoelectric current, induced by a surface acoustic wave propagating along a ballistic quantum channel, are considered. We focus on the large wave-amplitude case, in which it has been experimentally found that the…
We have investigated the response of the acoustoelectric current driven by a surface-acoustic wave through a quantum point contact in the closed-channel regime. Under proper conditions, the current develops plateaus at integer multiples of…
We present the experimental realization of different approaches to increase the amount of quantized current which is driven by surface acoustic waves through split gate structures in a two dimensional electron gas. Samples with driving…
A programmable quantum current generator based on the application of Ohm's law to quantum voltage and resistance standards has demonstrated a realization of the ampere from the elementary charge with a $10^{-8}$ relative uncertainty [J.…
We demonstrate the synchronization of current quantization in a parallel array of weakly coupled Josephson Junctions operating in the regime of the coherent quantum phase slip. The first quantized current step on the voltage-current…
A well-characterised sample of silicon tunable-barrier electron pump has been operated at a frequency of 2 GHz using a custom drive waveform, generating a pump current of 320 pA. Precision measurements of the current were made as a function…
We present a detailed study of the surface acoustic wave mediated quantized transport of electrons through a split gate device containing an impurity potential defined quantum dot within the split gate channel. A new regime of quantized…
The quantized current generated by a quantum dot pump is calculated numerically. The numerical simulation is done by dividing the time varying potential into many static potentials with a short time interval and calculating the electron…
We have studied the acoustoelectric current in single-electron pumps driven by surface acoustic waves. We have found that in certain parameter ranges two different sets of quantized steps dominate the acoustoelectric current versus…
Adiabatic pumping of electrons induced by surface acoustic waves (SAWs) in a ballistic quasi-1D quantum channel is considered using an exactly solvable tight-binding model for non-interacting electrons. The single-electron degrees of…
Electron pumps generate a macroscopic electric current by controlled manipulation of single electrons. Despite intensive research towards a quantum current standard over the last 25 years, making a fast and accurate quantised electron pump…
The acoustoelectric current induced by a surface acoustic wave (SAW) in a ballistic quantum point contact is considered using a quantum approach. We find that the current is of the "pumping" type and is not related to drag, i.e. to the…
Two quantized charge pumps are operated in parallel. The total current generated is shown to be far more accurate than the current produced with just one pump operating at a higher frequency. With the application of a perpendicular magnetic…
Recently a new explanation for the quantized current of the surface acoustic wave (SAW)-driven single electron pumps was suggested [1]. In the SAW-driven pumps the electrons are transported by the SAW along a one-dimensional semiconductor…
We present experimental results of high frequency quantized charge pumping through a quantum dot formed by the electric field arising from applied voltages in a GaAs/AlGaAs system in the presence of a perpendicular magnetic field B. Clear…
We systematically study the acousto-current of two-dimensional electron systems in the integer and fractional quantum Hall regimes using surface acoustic waves. We are able to separate the co-existing acoustic scattering and drag, when…
The effect of a perpendicular magnetic field on the quantized current induced by a surface acoustic wave in a quasi-1D channel is studied. The channel has been produced experimentally in a GaAs heterostructure by shallow etching techniques…
We derive a scaling law relating ADC bit depth to effective bandwidth for signals with $1/f^\alpha$ power spectra. Quantization introduces a flat noise floor whose intersection with the declining signal spectrum defines an effective cutoff…
Using standard microfabrication techniques it is now possible to construct devices, which appear to reliably manipulate electrons one at a time. These devices have potential use as building blocks in quantum computing devices, or as a…