Related papers: Single-parameter quantized charge pumping in high …
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 present a realization of quantized charge pumping. A lateral quantum dot is defined by metallic split gates in a GaAs/AlGaAs heterostructure. A surface acoustic wave whose wavelength is twice the dot length is used to pump single…
Non-adiabatic pumping of discrete charges, realized by a dynamical quantum dot in an AlGaAs/GaAs heterostructure, is studied under influence of a perpendicular magnetic field. Application of an oscillating voltage in the GHz-range to one of…
This paper investigates a scheme for quantized charge pumping based on single-parameter modulation. The device was realized in an AlGaAs-GaAs gated nanowire. We find a remarkable robustness of the quantized regime against variations in the…
Single-charge pumps are the main candidates for quantum-based standards of the unit ampere because they can generate accurate and quantized electric currents. In order to approach the metrological requirements in terms of both accuracy and…
We demonstrate single-electron pumping in a gate-defined carbon nanotube double quantum dot. By periodic modulation of the potentials of the two quantum dots we move the system around charge triple points and transport exactly one electron…
Controlled charge pumping in an AlGaAs/GaAs gated nanowire by single-parameter modulation is studied experimentally and theoretically. Transfer of integral multiples of the elementary charge per modulation cycle is clearly demonstrated. A…
We investigate spin and charge current through a quantum dot pumped by a time-varying magnetic field. Using the density matrix method, quantum rate equations for the electronic occupation numbers in the quantum dot are obtained and solved…
Precise manipulation of individual charge carriers in nanoelectronic circuits underpins practical applications of their most basic quantum property --- the universality and invariance of the elementary charge. A charge pump generates a net…
Semiconducting nanowires (NWs) are a versatile, highly tunable material platform at the heart of many new developments in nanoscale and quantum physics. Here, we demonstrate charge pumping, i.e., the controlled transport of individual…
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…
We consider pumping through a small quantum dot separated from the leads by two point contacts, whose conductances, $G_{1}$ and $G_{2}$, serve as pumping parameters. When the dot is pincched, we find that there is a "resonance line" in the…
We present experimental studies of the current pumped through a dynamic quantum dot over a wide range of magnetic fields. At low fields we observe repeatable structure indicating increased confinement of the electrons in the dynamic dot. At…
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…
We have incorporated an aluminum single electron transistor directly into the defining gate structure of a semiconductor quantum dot, permitting precise measurement of the charge in the dot. Voltage biasing a gate draws charge from a…
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…
Single-electron pumps based on semiconductor quantum dots are promising candidates for the emerging quantum standard of electrical current. They can transfer discrete charges with part-per-million (ppm) precision in nanosecond time scales.…
We propose a random matrix theory to describe the influence of a time-dependent external field on electron transport through open quantum dots. We describe the generation of the current by an oscillating field for the dot, connected to two…
In quantum metrology, semiconductor single-electron pumps are used to generate accurate electric currents with the ultimate goal of implementing the emerging quantum standard of the ampere. Pumps based on electrostatically defined tunable…
Adiabatically pumped charge, carried by non-interacting electrons through a quantum dot in a turnstile geometry, is studied as function of the strength of the two modulating potentials (related to the conductances of the two point-contacts…