Related papers: Tuning carbon nanotube bandgaps with strain
We use a simple picture based on the $\pi$ electron approximation to study the bandgap variation of carbon nanotubes with uniaxial and torsional strain. We find (i) that the magnitude of slope of bandgap versus strain has an almost…
Controlling the bandgap of carbon nanostructures is key to the development and mainstream application of carbon-based nanoelectronic devices. We report density functional theory calculations of the effect of silicon impurities on the…
We investigate the response of multi-walled carbon nanotubes to mechanical strain applied with an Atomic Force Microscope (AFM) probe. We find that in some samples, changes in the contact resistance dominate the measured resistance change.…
Electrostatic screening between carbon nanotubes (CNTs) in a small CNT bundle leads to a switching behavior induced by electric field perpendicular to the bundle axis. Using a first-principles method, we investigate the electronic…
We propose a microscopic model for a nanoelectromechanical system made by a radio-frequency driven suspended carbon nanotube (CNT) in the presence of an external magnetic field perpendicular to the current. As a main result, we show that,…
The electronic band structure of armchair carbon nanotubes may be considerably modified by potentials with angular dependence. Different angular modes V_q ~ cos(q*theta) have been studied within a tight-binding scheme. Using symmetry…
We propose a method to modulate the bandgaps in quasi-metallic carbon nanotubes using a transverse electric field. Unlike previous investigations, we include curvature effects of the nanotubes by incorporating both $\pi$- and…
We have evaluated the energies required to twist carbon nanotubes (NTs), and investigated the effects of these distortions on their electronic structure and electrical properties. The computed distortion energies are high, indicating that…
We have investigated the magnetoconductance of semiconducting carbon nanotubes (CNTs) in pulsed, parallel magnetic fields up to 60 T, and report the direct observation of the predicted band-gap closure and the reopening of the gap under…
In weakly buckled carbon nanotubes, the kink is an open, ovalized constriction where molecular-sized analytes and ions can pass. Moreover, in semiconducting tubes, the kink has an electronic bound state within the bandgap. This state is…
AFM manipulation was used to controllably stretch individual metallic single-walled carbon nanotubes (SWNTs). We have found that SWNTs can sustain elongations as great as 30% without breaking. Scanned gate microscopy and transport…
The newly synthesized ultrathin carbon nanothreads have drawn great attention from the carbon community. Here, based on first-principles calculations, we investigate the electronic properties of carbon nanothreads under the influence of two…
The temperature dependence of the band gap of semiconducting single-wall carbon nanotubes (SWNTs) is calculated by direct evaluation of electron-phonon couplings within a ``frozen-phonon'' scheme. An interesting diameter and chirality…
Carbon nanotube's large electro-mechanical coupling and robustness makes them attractive for applications where bending and buckling is present. But the nature of this coupling is not well understood. Existing theory treats only weak and…
We present a systematic analysis of the effect of radial deformation on the atomic and electronic structure of zigzag and armchair single wall carbon nanotubes using the first principle plane wave method. The nanotubes were deformed by…
The electronic properties of squashed arm-chair carbon nanotubes are modeled using constraint free density functional tight binding molecular dynamics simulations. Independent from CNT diameter, squashing path can be divided into {\it…
The electronic structure of finite-length armchair carbon nanotubes has been studied using several ab-initio and semi-empirical quantum computational techniques. The additional confinement of the electrons along the tube axis leads to the…
The high aspect ratio of carbon nanotubes makes them prone to bending. To know how bending affects the tubes is therefore crucial for tube identification and for electrical component design. Very few studies, however, have investigated…
We present first-principles calculations of quantum transport which show that the resistance of metallic carbon nanotubes can be changed dramatically with homogeneous transverse electric fields if the nanotubes have impurities or defects.…
We present many-body \textit{ab initio} calculations of the electronic and optical properties of semiconducting zigzag carbon nanotubes under uniaxial strain. The GW approach is utilized to obtain the quasiparticle bandgaps and is combined…