Journal of Computational and Theoretical Nanoscience 

About: Journal of Computational and Theoretical Nanoscience is an academic journal. The journal publishes majorly in the area(s): Carbon nanotube & Nanofluid. It has an ISSN identifier of 1546-1955. Over the lifetime, 4298 publications have been published receiving 25581 citations.

Spectral Phonon Transport Properties of Silicon Based on Molecular Dynamics Simulations and Lattice Dynamics

Abstract: Although the thermal conductivity of silicon has been studied before, current estimations for the phonon mean free paths have not provided full explanation of the strong size effects experimentally observed for various silicon micro and nanostructures. Since phonon relaxation time models are mostly semi-empirical, the mean free paths cannot be determined reliably and questions remain as to which polarizations, frequencies and wavelengths are dominant heat carriers. Here we have used a combination of equilibrium molecular dynamics simulations and lattice dynamics calculations to fully detail the spectral dependence of phonon transport properties in bulk silicon. By considering the frequency dependence of the specific heat, group velocities and mean free paths, we address these unresolved questions and examine the errors associated with isotropic and frequency averaged approximations. Simulation details, such as the convergence of results on the simulation time and extraction of phonon transport properties in different crystallographic directions, are also discussed.

Negative Refractive Index Materials

Abstract: The main directions of studies of materials with negative index of refraction, also called left-handed or metamaterials, are reviewed. First, the physics of the phenomenon of negative refraction and the history of this scientific branch are outlined. Then recent results of studies of photonic crystals that exhibit negative refraction are discussed. In the third part numerical methods for the simulation of negative index material configurations and of metamaterials that exhibit negative index properties are presented. The advantages and the shortages of existing computer packages are analyzed. Finally, details of the fabrication of different kinds of metamaterials are given. This includes composite metamaterials, photonic crystals, and transmission line metamaterials for different wavelengths namely radio frequencies, microwaves, terahertz, infrared, and visible light. Furthermore, some examples of practical applications of metamaterials are presented.

Five-Input Majority Gate, a New Device for Quantum-Dot Cellular Automata

Abstract: Science and Research Branch of IAU, Tehran, IranQuantum-dot Cellular Automata (QCA) is one of the most attractive technologies for computing atnano-scale. The principle logic element in QCA is majority gate. In this paper, a novel design for5-input majority gate is presented. A 5-input majority gate study has been proposed; however thisstudy has changed the scheme of basic QCA cells. The new proposed device reduces cell countsand area and uses conventional form of QCA cells. Accuracy of this design is proven by applyingsome simple physical substantiation and QCADesigner tool is used for verifying majority circuitlayout and functionality. Furthermore, a QCA Full-Adder is constructed using the new proposeddesign. Simulation results demonstrate that the proposed design of majority gates and Full-Adderresulted in significant improvements in designing logical circuits.