The quantum transport computations have been carried on four different width of zigzag graphene using a nonequilibrium Green’s function method combined with density functional theory. The computed properties are included transmittance spectrum, electrical current and quantum conductance at the 0.3V as bias voltage.  The considered systems were composed from one-layer graphene sheets differing w...

The theory and practice of polytypic programming is intimately connected with the initial algebra semantics of datatypes. This is both a blessing and a curse. It is a blessing because the underlying theory is beautiful and well developed. It is a curse because the initial algebra semantics is restricted to so-called regular datatypes. Recent work by R. Bird and L. Meertens (1998) on the semanti...

The effects of layer thickness and periodicity on thermoelectric properties of Si/Ge superlattice materials are studied through a non-equilibrium Green’s function (NEGF) computational approach. Results show an independence of Seebeck coefficient for increasing the number of superlattice periods. Additionally, a critical layer thickness is obtainable to achieve a favorable transmission spectrum ...

In this article, we demonstrate a reliable physics-based simulation approach to accurately model high-speed 0.53 Ga xmlns:xlink="http://www.w3.org/1999/xlink">0.47 As/AlAs double-barrier resonant tunneling diodes (RTDs). It relies on the nonequilibrium Green’s function (NEGF) formalism imp...

Graphene's isolation launched explorations of fundamental relativistic physics originating from the planar honeycomb lattice arrangement of the carbon atoms, and of potential technological applications in nanoscale electronics. Bottom-up fabricated atomically-precise segmented graphene nanoribbons, SGNRs, open avenues for studies of electrical transport, coherence, and interference effects in m...

An accurate and efficient algorithm for computing non-equilibrium Green’s functions has been developed and used in the simulations of a novel nanoscale MOSFET device structure. The method is based on the principle of nested dissection and demonstrates significant performance improvement from both speed and memory requirements points of view as compared to the state of the art recursive Green’s ...

this article explain unsuccessful iranian intellectuals' attempts in the fields of thoughts and politics through surveying ideas of ehsan tabari and jalal ale-ahmad. it tries to show that theirs ideas have been under hegemony of political formalism; so their naïve attitudes has converted their thought to an ideology which serve to political aims based on a political formalism. this article...

The performance of field effect transistors comprised of a zigzag graphene nanoribbon that is symmetrically doped with boron nitride (BN) as a channel material, is numerically studied for the first time. The device merit for digital applications is investigated in terms of the on-, the off- and the on/off-current ratio. Due to the strong effect of the substrate roughness on the performance of g...

We establish well-defined limits in which the time-dependent electronic currents across a molecular junction subject to a fluctuating environment can be quantitatively captured via the Landauer steady-state approximation. For this, we calculate the exact time-dependent non-equilibrium Green's function (TD-NEGF) current along a model two-site molecular junction, in which the site energies are su...