▎ 摘 要
We study the optical absorption properties of zigzag-edge graphene nanoribbons (ZGNRs) taking into account the Coulomb interaction effect in the Hartree-Fock approximation. The optical selection rules for the incident light polarized along the longitudinal and transverse directions are investigated. We demonstrate that the excitations from the edge states are essential for the optical properties of ZGNRs in the neutral case. With the chemical potential shifting away from the Dirac point, the optical conductivity is drastically enhanced in the low frequency region for the transverse polarized incident light. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3692171]