Related papers: Coherent quantum ratchets driven by tunnel oscilla…
A quantum dot weakly coupled to two normal metal leads exhibits resonant transmission when one of the dot energy levels lies within the applied bias window. But when the quantum dot is sidecoupled to the transport channel, transmission in…
Fluctuations of electric current in a spin valve consisting of a diffusive conductor connected to ferromagnetic leads and operated in the giant magnetoresistance regime are studied. It is shown that a new source of fluctuations due to…
Full counting statistics of electron transport is of fundamental importance for a deeper understanding of the underlying physical processes in quantum transport in nanoscale devices. The backaction effect from a detector on the nanoscale…
The electronic transport in a system of two quantum rings side-coupled to a quantum wire is studied via a single-band tunneling tight-binding Hamiltonian. We derived analytical expressions for the conductance, density of states and the…
Current-correlations are a very sensitive probe of the fluctuations of small conductors. For non-interacting particles injected from thermal sources there is a simple connection between the sign of correlations and statistics:…
We report an experimental study on the shot noise as well as the dc transport properties of a quantum point contact (QPC) whose conductance anomaly can be tuned electrostatically by the gate electrodes. By controlling the single QPC so that…
One of the many measures of the non-equilibrium nature of a system is the existence of a non-zero steady state current which is especially relevant for many biological systems. To this end, we study the non-equilibrium dynamics of a…
Based on the scattering matrix theory and non-equilibrium green function method, we have investigated the fluctuations of charge and spin current of the systems which consists of a quantum dot (QD) with a resonant level coupled to two…
Transport properties of two coupled Josephson junctions driven by ac currents and thermal fluctuations are studied with the purpose of determining dc voltage characteristics. It is a physical realization of directed transport induced by a…
The concept of thermal ratchets is extended to the system governed by quantum mechanics. We study a tight-binding model with an asymmetric periodic potential contacting with a heat bath under an external oscillating field as a specific…
It is shown that the resonance Kondo tunneling through a double quantum dot (DQD) with even occupation and singlet ground state may arise at a strong bias, which compensates the energy of singlet/triplet excitation. Using the…
A generic kind of quantum chaotic ratchet is introduced, based on initial states that are \emph{uniform} in phase space with the \emph{maximal possible} resolution of one Planck cell. Unlike a classical phase-space uniform density, such a…
A Josephson junction embedded in a dissipative circuit can be externally driven to induce nonlinear dynamics of its phase. Classically, under sufficiently strong driving and weak damping, dynamic multi-stability emerges associated with…
The transmission of electrons through a non-interacting tight-binding chain with an interacting side quantum dot (QD) is analized. When the Kondo effect develops at the dot the conductance presents a wide minimum, reaching zero at the…
A graph-theoretic analysis of the steady-state current noise in master equations under a finite thermodynamic force (affinity) is presented. The incidence matrix twisted by a finite affinity is not orthogonal to the standard cycle space,…
Experiments on the direction-resolved full-counting statistics of single-electron tunneling allow testing the fundamentally important Fluctuation Theorem (FT). At the same time, the FT provides a frame for analyzing such data. Here we…
Conductance through a system consisting of a wire with side-attached quantum dots is calculated. Such geometry of the device allows to study the coexistence of quantum interference, electron correlations and their influence on conductance.…
Coulomb drag between nanoscale conductors is of both fundamental and practical interest. Here, we theoretically study drag in a double quantum-dot (QD) system consisting of a biased drive QD and an unbiased drag QD coupled via a direct…
Single-electron tunneling processes through a double quantum dot can induce a lasing state in an electromagnetic resonator which is coupled coherently to the dot system. Here we study the noise properties of the transport current in the…
Quantum-resonance ratchets have been realized over the last ten years for the production of directed currents of atoms. These non-dissipative systems are based on the interaction of a Bose-Einstein condensate with an optical standing wave…