Time dependent spin transport through t-shaped double quantum dots embedded between two (half -metallic ScC bulk)‎ leads

الملخص EN

For the experimental and theoretical importance of the time – dependent spin transport through quantum dots structures, the electromagnetic field–assisted spin transport through T–shaped double quantum dots embedded between two not normal leads are studied and analyzed.

The time – dependent Hamiltonian, that describes the device, follows the tight binding scheme by taking all the spin dependent coupling interactions between the subsystems into consideration.

The theoretical treatment is accomplished using the time – evolution operator approach, since the equations of motion in the interaction representation for the time – evolution operator matrix elements are derived.

The thirty two intgro-differential equations of motion for both spin are solved numerically by using sixth order Runge Kutta method, since the error is checked in each step of time.

The energy dependent calculations are achieved by considering the density of states of the not normal leads.

While the adiabatic approximation is used to treat the effects of the external electromagnetic field characteristic (frequency and amplitude) theoretically.

In concern to the not normal leads, the study concentrated the first-principles full-potential linearized augmented plane-wave method (FPLAPW), this method depends on the use of the density functional theory to examine the structural, magnetic, and electronic characteristics of the bulk of Zinc-blende ScC.

This study has proven that both of the bulk ZB ScC is half- metallic ferromagnet at an equilibrium lattice constant of (0.5121 nm).

The main goal of our study is to investigate the effects of the electromagnetic field on the T–shaped double quantum dots device, so all the electronic properties of the device as well as the electromagnetic field parameters are taken into consideration in our treatment.

The role of the field frequency and the spin dependent coupling interaction are well analyzed and explained for the ScC bulk leads.