▎ 摘　　要

The low-frequency magneto-electronic excitations of armchair graphene nanoribbons (AGNRs) are calculated by the p(z)-orbital tight-binding model and random-phase-approximation. Zero-field plasmon shows a blue-shift in frequency as transferred momentum increases, but they are suppressed at smaller and larger transferred momenta due to Landau damping. With an increase in ribbon's width, plasmon occurs at lower frequency and exhibits weaker dispersion relation with transferred momentum. While magnetic field continuously increases, plasmon reveals lower frequency and sharper peak at small momentum. With the aid of magnetic field, for large-gapped AGNR new plasmon at finite temperature is created by the intraband transition and threshold transferred momentum is also reduced. On the other hand, the loss function of small-gapped AGNR exhibits two-peak structure due to the interplay between temperature and magnetic field. As temperature increases, magnetoplasmon frequency undergoes a blue- or red-shift strongly depending on boundary geometry.