Model Parameterization for Coherent Manipulation in Spin Current through FM-QD1-QD2-FM

Abstract

In this work, model parameterization for coherent manipulation, for serially coupled double quantum dots embedded between ferromagnetic leads (FM-QD1-QD2-FM), is presented. Theoretical model based to the non-equilibrium Green’s function approach is considered. Since the spin current and its spin channels are formulated incorporating the spin polarization and the type of spin configuration on the leads. Our model incorporates the inter-dot hopping, the intra-dot Coulomb correlation, the spin exchange energy and the coupling interactions between the quantum dots and leads. The results concerned to the parallel configuration at strong inter-dot coupling regime shows the preferable coherent state for spin down electrons only at relatively high polarization. While, for weak coupling regime and antiparallel configuration, the decoherent state is dominating. Interesting results have been concluded by calculating the molecular energy levels of the quantum dots. In all our calculations the same spin polarization on the leads is considered. The case of different spin polarization on the lead is also investigated but no unprecedented features are concluded as active region is symmetric.

Theoretical Investigation in Coherent Manipulation throughout the Calculation of the Local Density of States in FM-DQD-FM Device

“…Our calculations for the antiparallel configuration (in strong and weak regimes) show also decoherence state, since the bonding and antibonding states are not well separated (see Figs. [14][15][16][17].…”

“…The binding force between the two dots forms this energy gain [11][12][13]. In our earlier work, a mathematical model has constructed to study the transport properties of serially DQD embedded between two ferromagnetic leads [14]. As an additional stride we investigate the local density of states (DOS) of the DQD system accurately.…”

The Charge and Spin Thermoelectric Properties across Double Quantum Dots Serially Coupled to Ferromagnetic Leads: The Case of Parallel Magnetic Configuration

“…Refs. [29,30]. For the purpose of access to charge and spin thermoelectric coefficients we need to find all the relevant transport integrals related to these coefficients, i.e.…”