The recent fabrication of graphene nanoribbon GNR field-effect transistors poses a challenge for firstprinciples modeling of carbon nanoelectronics due to many thousand atoms present in the device. The state of the art quantum transport algorithms, based on the nonequilibrium Green function formalism combined with the density-functional theory NEGF-DFT , were originally developed to calculate s...

The understanding and modeling of inelastic scattering thermal phonons at a solid/solid interface remain an open question. We present fully quantum theoretical scheme to quantify the effect anharmonic phonon-phonon via nonequilibrium Green's function (NEGF) formalism. Based on real-space rate matrix, decomposition interfacial spectral energy exchange is made into contributions from local nonloc...

A deeper understanding of quantum effects in nano-electronic devices helps to improve the functionality and to develop new device types. The performance of carbon nanotube (CNT) field-effect transistor is studied using the non-equilibrium Green’s function (NEGF) formalism. The effects of elastic and inelastic scattering and the impact of parameters, such as electron–phonon coupling strength and...

The central computation in atomistic, quantum transport simulation consists in solving the Schrödinger equation several thousand times with non-equilibrium Green’s function (NEGF) equations. In the NEGF formalism, a numerical linear algebra problem is identified related to the computation of a sparse inverse subset of general sparse unsymmetric matrices. The computational challenge consists in ...

The non-equilibrium Green’s function (NEGF) formalism provides a sound conceptual basis for the devlopment of atomic-level quantum mechanical simulators that will be needed for nanoscale devices of the future. However, this formalism is based on concepts that are unfamiliar to most device physicists and chemists and as such remains relatively obscure. In this paper we try to achieve two objecti...

INTRODUCTION With the shrinking dimension of electronic devices, quantum transport attracts increasing interest. The non-equilibrium Green’s function (NEGF) formalism [1] provides a very general framework for quantum transport, but it is numerically expensive when applied on atomistic tight binding representations. So far, computational burden (in memory and CPU time) limits the maximum diamete...

Asymmetric I /V curves with respect to the polarity of the voltage bias were observed in the Hg /Au junctions containing bilayers of alkanethiols of different chain length. A larger current resulted when a negative bias was applied to the metal carrying a longer chain alkanethiol monolayer. This behavior is simulated using a single molecule junction model, within the frameworks of the extended ...

In this paper, we present the mathematical and implementation details of an ab initio method for calculating spin-polarized quantum transport properties of atomic scale spintronic devices under external bias potential. The method is based on carrying out density functional theory (DFT) within the Keldysh non-equilibrium Green's function (NEGF) formalism to calculate the self-consistent spin den...

The dimensions of electronic devices are rapidly decreasing and there is a need for a new generation of modeling tools that can accurately calculate the electrical properties of devices where atomic scale details and quantum effects are important. A promising framework for such calculations is density functional theory within the non-equilibrium Green's function formalism (NEGF-DFT). In this pa...

Self assembled quantum dots have shown a great promise as a leading candidate for infrared detection at room temperature. In this paper, a theoretical model of the absorption coefficient of quantum dot devices is presented. Both of bound to bound absorption and bound to continuum absorption are taken into consideration in this model. This model is based on the effective mass theory and the Non ...