Related papers: Current and Noise in a FM/quantum dot/FM System
We study the spin-dependent transport through a quantum dot coupled to two ferromagnetic electrodes using the equation of motion method for the nonequilibrium Green's functions. Our results show that the conductance and the density of…
We present measurements of current noise in quantum point contacts as a function of source-drain bias, gate voltage, and in-plane magnetic field. At zero bias, Johnson noise provides a measure of the electron temperature. At finite bias,…
The Fano factor stability diagram of a C$_{3v}$ symmetric triangular quantum dot is analysed for increasing electron fillings $N$. At low filling, conventional Poissonian and sub-Poissonian behavior is found. At larger filling, $N\ge 2$, a…
We theoretically establish mutual relations among magnetic momentum, heat, and fluctuations of propagating magnons in a ferromagnetic insulating junction in terms of noise and the bosonic Wiedemann-Franz (WF) law. Using the…
Based on Keldysh's nonequilibrium Green function method, the spin-dependent transport properties in a ferromagnet-quantum dot (QD)-ferromagnet coupled system are investigated. It is shown the spin current shows quite different…
We show that the breakdown of the Wiedemann-Franz law due to electron--electron scattering in diffusive spin valves may result in a strong suppression of the Fano factor that describes the ratio between shot noise and average current. In…
We examine cross-correlations (CCs) in the tunneling currents through two parallel interacting quantum dots coupled to four independent ferromagnetic electrodes. We find that when either one of the two circuits is in the parallel…
We analyze shot noise in a magnetic tunnel junction with a two-level quantum dot attached to the magnetic electrodes. The considerations are limited to the case when some transport channels are suppressed at low temperatures. Coupling of…
We consider a single-level quantum dot tunnel-coupled to one normal and one superconducting lead. We employ a diagrammatic real-time approach to calculate the finite-frequency current noise for subgap transport. The noise spectrum gives…
We present a theoretical study of current noise of a resonant tunnel junction coupled to a nanomechanical oscillator within the non-equilibrium Green's function technique. An arbitrary voltage is applied to the tunnel junction and electrons…
We compute the spin current rectification coefficient of a non-equilibrium quantum dot subject to a spin bias and an {\it ac} charge bias with small amplitude. As a function of the position of the resonant level the spin current…
We study spin-dependent conductance in a system composed of a ferromagnetic (FM) Scanning Tunneling Microscope (STM) tip coupled to a metallic host surface with an adatom. The Kondo resonance is taken into account via the Doniach-Sunjic…
By using the drone-fermion representation and the Schwinger-Keldysh approach, we calculate the current noise and the charge noise for a single-electron transistor in the non-equilibrium state in the presence of large quantum fluctuation of…
We formulate a theory for shot noise in quantum nanoelectromechanical systems. As a specific example, the theory is applied to a quantum shuttle, and the zero-frequency noise, measured by the Fano factor F, is computed. F reaches very low…
In the presence of spatial variation of the magnetization direction, electric current noise causes a fluctuating spin-transfer torque that increases the fluctuations of the ferromagnetic order parameter. By the fluctuation-dissipation…
We theoretically compare transport properties of Fano-Kondo effect with those of Fano effect. We focus on shot noise characteristics of a triple quantum dot (QD) system in the Fano-Kondo region at zero temperature, and discuss the effect of…
We investigate the equilibrium and out-of-equilibrium Kondo effects in a single-level interacting quantum dot connected to two ferromagnetic leads. Within the non-crossing approximation, we calculate the total density of states (DOS), the…
We systematically study the influence of ferromagnetic leads on the Kondo resonance in a quantum dot tuned to the local moment regime. We employ Wilson's numerical renormalization group method, extended to handle leads with a spin…
Numerical results are presented for transport properties of two coupled double-level quantum dots. The results strongly suggest that under appropriate circumstances the dots can develop a novel ferromagnetic (FM) correlation at…
We present a theoretical study based on the Anderson model of the transport properties of a Kondo impurity (atom or quantum dot) connected to ferromagnetic leads, which can sustain a non-equilibrium spin current. We analyze the case where…