相关论文: A Quantum Singlet Pump

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 present a diagrammatic real-time approach to adiabatic pumping of electrons through interacting quantum dots. Performing a systematic perturbation expansion in the tunnel-coupling strength, we compute the charge pumped through a…

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…

We study non-adiabatic charge pumping through single-level quantum dots taking into account Coulomb interactions. We show how a truncated set of equations of motion can be propagated in time by means of an auxiliary-mode expansion. This…

We investigate two schemes for pumping spin adiabatically from a ferromagnet through an interacting quantum dot into a normal lead, which exploit the possibility to vary in time the ferromagnet's magnetization, either its amplitude or its…

We study two different parametric pumps for interacting quantum wires, one for pumping spin currents, the other for charge currents. We find that the spin or charge pumped per cycle has a non-universal crossover, depending on pumping…

Statistics of charge transport in an adiabatic pump are determined by the dynamics of the scattering matrix S(t). We show that, up to an integer offset, the statistics depend only on the corresponding path N(t)=S^\dagger\sigma_3 S in the…

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 analyze quantum charge pumping in an open ring with a dot embedded in one of its arms. We show that cyclic driving of the dot levels by a \textit{single} parameter leads to a pumped current when a static magnetic flux is simultaneously…

We study adiabatic pumping through a two-level quantum dot with spin-orbit coupling. Using a diagrammatic real-time approach, we calculate both the pumped charge and spin for a periodic variation of the dot's energy levels in the limit of…

We present a prescription for generating pure spin current or spin selective current, based on adiabatic quantum pumping in a tight-binding model of a one dimensional conductor. A formula for the instantaneous pumped current is derived…

We propose a mechanism by which an open quantum dot driven by two ac (radio frequency) gate voltages in the presence of a moderate in-plane magnetic field generates a spin polarized, phase coherent dc current. The idea combines adiabatic,…

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…

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…

We consider adiabatic charge transport through an almost open quantum dot. We show that the charge transmitted in one cycle is quantized in the limit of vanishing temperature and one-electron mean level spacing in the dot. The explicit…

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…

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…

We investigate adiabatic charge pumping in disordered system in one dimension with open and closed boundary conditions. In contrast to the Thouless charge pumping, the system has no gap even though all the states are localized, i.e., strong…

The sharply quantized transport observed in the integer quantum Hall effect can be explained via a simple one-dimensional model with a time-periodic, adiabatically varying potential in which electronic charge is pumped from one side of the…

Non-adiabatic charge pumping through a single-level quantum dot with periodically modulated parameters is studied theoretically. By means of a quantum-master-equation approach the full counting statistics of the system is obtained. We find…