Band-gap formation in ( n , 0 ) single-walled carbon nanotubes ( n = 9 , 12 , 15 , <mml…
2005; American Physical Society; Volume: 72; Issue: 7 Linguagem: Inglês
10.1103/physrevb.72.073404
ISSN1550-235X
Autores Tópico(s)Boron and Carbon Nanomaterials Research
ResumoWe study the electronic structure of the carbon nanotube theoretically by the first-principles techniques using the local-density approximation (LDA) with the many-body correction in the GW approximation. We find that the (9,0) tube is gapful irrespective of naive expectation from the graphene band structure. All of the $\ensuremath{\pi}\text{\ensuremath{-}}\ensuremath{\sigma}$ hybridization effect, lattice relaxation effect, and many-body effect due to electron interaction enhance the band gap, and the value is as large as $0.17\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ when taking into account all effects. For the $(n,0)$ nanotubes with $n=9$, 12, 15, and 18, the LDA gap is found to range from $0.08\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}0.02\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$. These sizable gap values obtained by the most reliable methods to date shed light on the classification of carbon nanotubes by their electronic transport properties.
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