相关论文: Different quantization mechanisms in single-electr…
Quantum pumping holds great potential for future applications in micro- and nanotechnology. Its main feature, dissipationless charge transport, is theoretically possible via several different mechanisms. However, since no unambiguous…
A dc current induced in a quantum constriction by a traveling acoustic wave (or by non-equilibrium ballistic phonons) is considered. We show that in many important situations the effect is originated from acoustically-induced scattering…
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…
We propose a quantum pump mechanism based on the particular properties of graphene, namely chirality and bipolarity. The underlying physics is the excitation of evanescent modes entering a potential barrier from one lead, while those from…
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 describe in detail a set of ideas for implementing qubits, quantum gates and quantum gate networks in a semiconductor heterostructure device. Our proposal is based on an extension of the technology used for surface acoustic wave (SAW)…
Piezoelectric surface acoustic waves (SAWs) are powerful for investigating and controlling elementary and collective excitations in condensed matter. In semiconductor two-dimensional electron systems SAWs have been used to reveal the…
Transport measurement, which applies an electric field and studies the migration of charged particles, i.e. the current, is the most widely used technique in condensed matter studies. It is generally assumed that the quantum phase remains…
We present results for non-adiabatic single-parameter pumping in a ballistic graphene field-effect transistor. We investigate how scattering from an ac-driven top gate results in dc charge current from source to drain in an asymmetric setup…
A surface-acoustic-wave (SAW) driven light-emitting-diode structure that can implement a single-photon-source for quantum-cryptography applications is demonstrated. Our lateral n-i-p junction is realized starting from an undoped GaAs/AlGaAs…
We propose an experiment to observe interference of a single electron as it is transported along two parallel quasi-one-dimensional channels trapped in a single minimum of a travelling periodic electric field. The experimental device is a…
We describe the interaction of surface acoustic waves with electrons in an array of quantum wires, patterned out of a two dimensional electron gas. Two specific geometries are considered, in which the surface acoustic wave travels parallel,…
We investigate a recently developed scheme for quantized charge pumping based on single-parameter modulation. The device was realized in an AlGaAl-GaAs gated nanowire. It has been shown theoretically that non-adiabaticity is fundamentally…
Surface acoustic waves (SAWs) strongly modulate the shallow electric potential in piezoelectric materials. In semiconductor heterostructures such as GaAs/AlGaAs, SAWs can thus be employed to transfer individual electrons between distant…
The quantized surface acoustic wave (SAW) in the piezoelectric medium has recently been studied, and is used to control electric dipoles of quantum systems via the electric field produced through piezoelectric effect. However, it is not…
We report electron counting experiments in a silicon metal-oxide-semiconductor quantum dot architecture which has been previously demonstrated to generate a quantized current in excess of 80 pA with uncertainty below 30 parts per million.…
We utilize a time-periodic ratchet-like potential modulation imposed onto a two-dimensional electron system inside a GaAs/Al$_x$Ga$_{1-x}$As heterostructure to evoke a net dc pumping current. The modulation is induced by two sets of…
A one-dimensional system with two $\delta$-like barriers or wells bi-chromaticaly oscillating at frequencies $\omega$ and $2\omega$ is considered. The alternating signal leads to the direct current across the structure (even in a symmetric…
We report on non-adiabatic transport through a double quantum dot under irradiation of surface acoustic waves generated on-chip. At low excitation powers, absorption and emission of single and multiple phonons is observed. At higher power,…
A quantum pumping mechanism which produces dc current or voltage in response to a cyclic deformation of the confining potential in an open quantum dot is reported. The voltage produced at zero current bias is sinusoidal in the phase…