相关论文: Quantum pumping: Coherent Rings versus Open Conduc…
In the adiabatic and weak-modulation quantum pump, net electron flow is driven from one reservoir to the other by absorbing or emitting an energy quantum $\hbar \omega $ from or to the reservoirs. In our approach, high-order dependence of…
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…
Quantum pumping in closed systems is considered. We explain that the Kubo formula contains all the physically relevant ingredients for the calculation of the pumped charge ($Q$) within the framework of linear response theory. The relation…
Current can be pumped through a closed system by changing parameters (or fields) in time. Linear response theory (the Kubo formula) allows to analyze both the charge transport and the associated dissipation effect. We make a distinction…
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 study the adiabatic quantum pumping characteristics in the graphene modulated by two oscillating gate potentials out of phase. The angular and energy dependence of the pumped current is presented. The direction of the pumped current can…
During an adiabatic pumping cycle a conventional two barrier quantum device takes an electron from the left lead and ejects it to the right lead. Hence the pumped charge per cycle is naively expected to be $Q \le e$. This zero order…
Pumping of charge (Q) in a closed ring geometry is not quantized even in the strict adiabatic limit. The deviation form exact quantization can be related to the Thouless conductance. We use Kubo formalism as a starting point for the…
We consider quantum charge pumping of electrons across a superconducting double barrier structure in the adiabatic limit. The superconducting barriers are assumed to be reflection-less so that an incident electron on the barrier can either…
We introduce a mathematical setup for charge transport in quantum pump connected to a number of external leads. It is proved that under rather general assumption on the Hamiltonian describing the system, in the adiabatic limit, the current…
In a mesoscopic system, under zero bias voltage, a finite charge is transferred by quantum adiabatic pumping by adiabatically and periodically changing two or more control parameters. We obtained expressions for the pumped charge for a ring…
Quantum adiabatic pumping of charge and spin between two reservoirs (leads) has recently been demonstrated in nanoscale electronic devices. Pumping occurs when two or more system parameters are varied in a cyclic manner and sufficiently…
Time periodic perturbations of an electron system on a ring are examined. For small frequencies periodic small amplitude perturbations give rise to side band currents which in leading order are inversely proportional to the frequency. These…
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 investigate a quantum pump which in addition to its dynamic pump parameters is subject to oscillating external potentials applied to the contacts of the sample. Of interest is the rectification of the ac currents flowing through the…
A quantum pump device involving magnetic barriers produced by the deposition of ferro magnetic stripes on hetero-structure's is investigated. The device for dc- transport does not provide spin-polarized currents, but in the adiabatic…
We study charge and spin transport through an interacting quantum wire, caused by backscattering off an effective impurity potential with a periodic time-dependence. The adiabatic regime of this pump for charge and spin is shown to depend…
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 study directed transport in periodically forced scattering systems in the regime of fast and strong driving where the dynamics is mixed to chaotic and adiabatic approximations do not apply. The model employed is a square potential well…
The charge current adiabatically pumped through a mesoscopic region coupled to a classical variable obeying a nonlinear dynamics is studied within the scattering matrix approach. Due to the nonlinearity in the dynamics of the variable, a…