Journal ArticleDOI
Energy gaps of semiconducting nanotubules.
H. Yorikawa,Shinji Muramatsu +1 more
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TLDR
An approximate expression for E, which can be applicable even to small-radius semiconducting tubules, is presented and it is shown that the E is well correlated with a fraction of the \ensuremath{\sigma} component in the wave functions for the conduction-band bottom and valence-band top.Abstract:
The effect of the mixing between \ensuremath{\pi} and \ensuremath{\sigma} orbitals upon the energy gaps (${\mathit{E}}_{\mathit{g}}$'s) of semiconducting carbon nanotubules has been theoretically studied within the tight-binding approximation. The magnitude of a chirality-dependent energy gap (${\mathit{E}}_{\mathrm{\ensuremath{\theta}}}$) has been estimated. This term cannot be neglected for tubules with a small radius. The relation of ${\mathit{E}}_{\mathit{g}}$ to R, ${\mathit{E}}_{\mathit{g}}$\ensuremath{\propto}${\mathit{R}}^{\mathrm{\ensuremath{-}}1}$, no longer holds for small-radius tubules. An approximate expression for ${\mathit{E}}_{\mathit{g}}$, which can be applicable even to small-radius semiconducting tubules, is presented. In addition, it is shown that the ${\mathit{E}}_{\mathrm{\ensuremath{\theta}}}$ is well correlated with a fraction of the \ensuremath{\sigma} component in the wave functions for the conduction-band bottom and valence-band top.read more
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Systematic ab initio study of curvature effects in carbon nanotubes
TL;DR: In this paper, the authors investigated curvature effects on geometric parameters, energetics, and electronic structure of zigzag nanotubes with fully optimized geometries from first-principle calculations.
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TL;DR: In this article, a tight-binding model for carbon nanotubes in a magnetic field perpendicular to the axis was proposed and the validity of the k · p theory was examined.
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Salim Ciraci,Sefa Dag,Taner Yildirim,Oguz Gulseren,Ramazan Tuğrul Senger,Ramazan Tuğrul Senger +5 more
TL;DR: In this article, the authors examine selected physical properties of bare carbon nanotubes, and then study how the mechanical and electronic properties of different tubes can be modified by radial strain, structural defects and adsorption of foreign atoms and molecules.
Journal ArticleDOI
Theoretical study of third-order nonlinear optical response of semiconductor carbon nanotubes
Vl.A. Margulis,T.A. Sizikova +1 more
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