Abstract We compute sum of the two the lowest Lyapunov exponents γ_(2N−1) + γ_2N of a tight-binding model for an single-wall armchair carbon nanotube with point impurities to lowest (second) order in the disorder parameter λ. The result is that γ_(2N−1) + γ_2N ∼ (λ^2)(N^−1) , where N is the number of hexagons around the perimeter. This is similar to the result of Schulz-Baldes [20] for the standard Anderson model on a strip, but because there are only two conducting channels near the Fermi level (centre of the spectral band), this implies that the scattering length is proportional to the diameter of the tube as predicted by Todorov and White [10].

Url http://dair.dias.ie/484/

Collections Ireland -> DAIR -> Open Access DRIVERset
Ireland -> DAIR -> Type = Article
Ireland -> DAIR -> Status = Preprint