Temperature-induced plasma excitations in gapped graphene and silicene

Both closed-form analytic and numerical results are presented for the polarization function, as well as the plasmon excitations of gapped graphene and silicene. The calculations are carried out within the random phase approximation (RPA). We investigate the behavior of the plasmon dispersion as a function of sublattice potential difference in silicene. These results could be used to compare the effective mass model with the tight-binding approximation at finite temperature in which spin-orbit coupling is included.