相关论文: An Adiabatic Quantum Electron Pump

Spin-dependent diffraction occurs in helimagnet-related transport processes. In this work, we investigated quantum pumping properties in the normal-metal/helimagnet/normal-metal heterostructure driven by two out of phase time-dependent gate…

We introduce a method where successive coordinate transformations are applied to decrease the error in the adiabatic master equation resulting from truncation in the local adiabatic parameter. Our method reduces the nonphysical behaviour…

Current induced forces are not only related with the discrete nature of electrons but also with its quantum character. It is natural then to wonder about the effect of decoherence. Here, we develop the theory of current induced forces…

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 present a theoretical study of the electronic transport through a many-level quantum dot driven by time-dependent signals applied at the contacts to the leads. If the barriers oscillate out of phase the system operates like a turnstile…

We have developed a general theory for a parametric pump consisting of a nonmagnetic system with two ferromagnetic leads whose magnetic moments orient at an angle $\theta$ with respect to each other. In this theory, the leads can maintain…

We provide provide a detailed study of biasless coherent transport of singlet electron pairs in one-dimensional (1D) channels induced by electron-electron interactions that are time-varying in certain spatially localized regions of the…

For an open quantum system, we investigate the pumped current induced by a slow modulation of control parameters on the basis of the quantum master equation and full counting statistics. We find that the average and the cumulant generating…

Using a tight-binding model, we study one-parameter charge pumping in a one-dimensional system of non-interacting electrons. An oscillating potential is applied at one site while a static potential is applied in a different region. Using…

Pumps are transport mechanisms in which direct currents result from a cyclic evolution of the potential. As Thouless has shown, the pumping process can have topological origins, when considering the motion of quantum particles in spatially…

A confined system of non-interacting electrons, subject to the combined effect of a time-dependent potential and different external chemical-potentials, is considered. The current flowing through such a system is obtained for arbitrary…

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 demonstrate the operation of a quantum spin pump based on cyclic radio-frequency excitation of a GaAs quantum dot, including the ability to pump pure spin without pumping charge. The device takes advantage of bidirectional mesoscopic…

We numerically study the parametric pumped current when magnetic field is applied both in the adiabatic and non-adiabatic regimes. In particular, we investigate the nature of pumped current for systems with resonance as well as…

We study the relation between quantum pumping of charge and the work exchanged with the driving potentials in a strongly interacting ac-driven quantum dot. We work in the large-interaction limit and in the adiabatic pumping regime, and we…

Adiabatic quantum pumping in noninteracting, phase coherent quantum dots is elegantly described by Brouwer's formula. Interactions within the dot, while suppressing phase coherence, make Brouwer's formalism inapplicable. In this paper, we…

Adiabatic pumping is characterized by a geometric contribution to the pumped charge, which can be non-zero even in the absence of a bias. However, as the driving speed is increased, non-adiabatic excitations gradually reduce the pumped…

We analyze the charge and spin pumping in an interacting dot within the almost adiabatic limit. By using a non-equilibrium Green's function technique within the time-dependent slave boson approximation, we analyze the pumped current in…

We analyze the operation of a molecular machine driven by the non-adiabatic variation of external parameters. We derive a formula for the integrated flow from one configuration to another, obtain a "no-pumping theorem" for cyclic processes…

Nanoscopic rings pierced by external magnetic fields and asymmetrically connected to wires behave in sharp contrast with classical expectations. By studying the real-time evolution of tight-binding models in different geometries, we show…