Showing papers by "Chao Cao published in 2007"
TL;DR: In this article, the strain dependence of electronic structure and transport properties of (6,0) carbon nanotubes has been thoroughly studied using first-principles calculations in conjunction with Green's function techniques.
Abstract: Strain dependence of electronic structure and transport properties of (6,0) carbon nanotubes has been thoroughly studied using first-principles calculations in conjunction with Green's function techniques. We have found that the quantum conductance is very sensitive to structural deformation and relaxation. The conductance decreases monotonically with increasing strain, for both compression and elongation. In an elongated tube, strain-induced electron localization is the dominating mechanism that controls the contribution of molecular orbitals to conductance. Transport properties are also drastically affected by the presence of defects. Our results have demonstrated that the electronic transport properties of a nanoscale device are closely related to the nature of the band structure of the metallic lead, the details of chemical bonding in the scattering region, and the interaction between Bloch states and the molecular orbitals.
39 citations
TL;DR: A relatively straightforward way to integrate existing software packages into a full multi-scale simulation package in which each application runs in its own address space and there is no run-time intervention by the researcher.
24 citations
TL;DR: It is shown that water not only substantially weakens a silica nanochain that has been the focus of much recent research but also leads to novel proton conduction in the SiO2 chain, a string of orthogonal two-membered rings.
Abstract: A basic issue in nanoscale systems is whether large-scale behavior occurs or not At and above the mesoscale, the water-silica interaction is known to have large effects, eg, the geological importance of hydrolytic weakening Here, we show that water not only substantially weakens a silica nanochain that has been the focus of much recent research but also leads to novel proton conduction The SiO2 chain consists of a string of orthogonal (planes alternating vertically and horizontally) two-membered rings We treat two cases of adjacent water to understand both local and collective motion in the system The first is two water molecules, the second is a water monolayer film that coats the entire chain Structure, charge separation, stress dependent bond breaking and formation, and proton conduction are discussed based on results obtained at the room temperature The simulations have been performed using both first-principles molecular dynamics and a novel multiscale quantum-classical software system
16 citations
TL;DR: In this article, an environment dependent dynamic charge potential for silica was developed based on density functional theory (DFT) for predicting energy and relative energy of a larger suite of silica nanostructures.
9 citations
Journal Article•
2 citations