Optical response of finite-length carbon nanotubes

Optical response of finite-length metallic carbon nanotubes is calculated including effects of induced edge charges in a self-consistent manner. The results show that the main resonance corresponding to excitation of the fundamental plasmon mode with wave vector $\pi/l$ with $l$ being the tube length is quite robust and unaffected. This arises because the strong electric field associated with edge charges is screened and decays rapidly inside the nanotube. For higher-frequency resonances, the field starts to be mixed and tends to shift resonances to higher frequencies.