Plasmon of bilayer armchair graphene nanoribbons: Influence of temperature and electric field

Band structures of bilayer armchair graphene nanoribbons (BLAGNRs) under the electric field are calculated in the tight-binding model. While the electric field increases, low-energy dispersions with many local maxima and minima lead to oscillatory band-gaps inducing semiconductor-metal or metal-semiconductor transitions. The dielectric function are further evaluated by the random-phase-approximation to obtain plasmon spectra. At zero field, temperature can enhance the plasmon spectra and change the plasmon frequency for the metallic BLAGNR. As the electric field increases, plasmon spectra could cover a wider range of frequency. With increasing temperature, plasmon dispersion relations further exhibit two branches of resonance mode and show different momentum-dependences. In addition, gapped BLAGNRs also exhibit richer field-modulated plasmon spectra at different temperatures. Effects of the electric field and temperature on low-frequency plasmons of BLAGNRs show a significant geometry-dependence that could provide more extensive applications in nanoplasmonics.

Automated summary

Band structures of bilayer armchair graphene nanoribbons (BLAGNRs) are calculated under an electric field in the tight-binding model. The electric field induces oscillatory band-gaps, leading to transitions between semiconductor and metal. The dielectric function is evaluated to obtain plasmon spectra, which are affected by temperature and exhibit different momentum-dependences.