Related papers: Gigahertz quantized charge pumping in graphene qua…
We study single-parameter quantized charge pumping via a semiconductor quantum dot in high magnetic fields. The quantum dot is defined between two top gates in an AlGaAs/GaAs heterostructure. Application of an oscillating voltage to one of…
We perform in-situ detection of individual electrons pumped through a single-electron turnstile based on ultrasmall normal metal - insulator - superconductor tunnel junctions. In our setup, limited by the detector bandwidth, at low…
The Electron Counting Capacitance Standard currently pursued at PTB aims to close the Quantum Metrological Triangle with a final precision of a few parts in 10^7. This paper reports the considerable progress recently achieved with a new…
In situ tunable radio-frequency charge detection is used for the determination of the tunneling rates into and out of a graphene single quantum dot connected to only one lead. An analytical model for calculating these rates in the…
The quantum Hall effect (QHE) is a cornerstone in the new International System of Units (SI), wherein the base units are derived from seven fundamental constants such as Planck's constant h and elementary charge e. Graphene has…
We report electronic transport experiments on a graphene single electron transistor. The device consists of a graphene island connected to source and drain electrodes via two narrow graphene constrictions. It is electrostatically tunable by…
Usually, graphene is used in its horizontal directions to design novel concept devices. Here, we report a single electron tunneling diode based on quantum tunneling through a vertical graphene two-barrier junction. The junction is formed by…
Charge carriers in the quantum Hall regime propagate via one-dimensional conducting channels that form along the edges of a two-dimensional electron gas. Controlling their transmission through a gate-tunable constriction, also called…
Graphene, a unique two-dimensional material of carbon in a honeycomb lattice, has brought remarkable breakthroughs across the domains of electronics, mechanics, and thermal transport, driven by the quasiparticle Dirac fermions obeying a…
Realizing graphene's promise as an atomically thin and tunable platform for fundamental studies and future applications in quantum transport requires the ability to electrostatically define the geometry of the structure and control the…
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…
The mechanism of single-charge pumping using a dynamic quantum dot needs to be precisely understood for high-accuracy and universal operation toward applications to quantum current standards and quantum information devices. The type of…
We present real-time detection measurements of electron tunneling in a graphene quantum dot. By counting single electron charging events on the dot, the tunneling process in a graphene constriction and the role of localized states are…
Ten years have passed since the beginning of graphene research. In this period we have witnessed breakthroughs both in fundamental and applied research. However, the development of graphene devices for mass production has not yet reached…
We investigate a graphene quantum pump, adiabatically driven by two thin potential barriers vibrating around their equilibrium positions. For the highly doped leads, the pumped current per mode diverges at the Dirac point due to the more…
Due to Klein tunneling, electrostatic confinement of electrons in graphene is not possible. This hinders the use of graphene for quantum dot applications. Only through quasi-bound states with finite lifetime has one achieved to confine…
Presented in this paper is a proof-of-concept for a new approach to single electron pumping based on a Single Atom Transistor (SAT). By charge pumping electrons through an isolated dopant atom in silicon, precise currents of up to 160 pA at…
We report on charge detection in electrostatically-defined quantum dot devices in bilayer graphene using an integrated charge detector. The device is fabricated without any etching and features a graphite back gate, leading to high quality…
Single-electron pumps based on isolated impurity atoms have recently been experimentally demonstrated. In these devices the Coulomb potential of an atom creates a localised electron state with a large charging energy and considerable…
We study an adiabatic quantum pump effect in a two terminal graphene device with two oscillating square electric barriers and a stationary magnetic barrier using the scattering matrix approach. The model employs the low-energy Dirac…