Effects of intertube interaction on the linear optical properties of the double-walled carbon nanotubes

The linear optical properties of double-walled carbon nanotubes (DWNTs) are studied within the tight-binding model, the gradient approximation and the sum-over-state (SOS) method. It is found that, due to intertube interaction, absorption peaks of the constituents may be slightly modified, except for little ones which are strongly reduced; in addition, a lot of new absorption peaks are produced. Our studies also show that these effects of intertube interaction are not significantly dependent on the tube length, chirality and commensurability.