A monopole-dipole model to compute the polarization of metallic carbon nanotubes

We present a monopole-dipole model to compute the polarization of metallic carbon nanotubes. The parameters of this model are adjusted on experimental data. In particular, we aimed at reproducing the mean polarizability of C60 and C70, the transverse polarizability of some carbon nanotubes, as well as the internal over external value ratio of transverse electric fields. As an application, we compute the axial polarizability of finite (5,5) carbon nanotubes. The comparison of these results with those obtained using other techniques shows that the consideration of net charges gives a better account of the metallicity of this kind of nanotubes.