▎ 摘　　要

Graphene nanoribbons (GNRs) exhibit novel and special electronic and optical properties with promising technological applications. The gate modulation on angle-resolved photoabsorption spectra of zigzag-edge GNRs (ZGNRs) is investigated based on the Hubbard model in the Hartree-Fock approximation. By examining the electron transition processes and the optical selection rules taking into account the Coulomb interaction effect, we demonstrate that the excitations from the edge states of ZGNRs are essential for the optical properties in the neutral case, and show the energy of the absorption peaks has the dispersion and splitting effects with increasing momentum transfer from the incident light. By modulating the chemical potential of ZGNRs, the intraband transitions which are forbidden for the neutral ZGNRs at zero temperature become important for the low energy optical properties, and a Drude peak of the optical conductivity emerges in the low frequency region. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4795124]