  In this study we report our numerical results on finite temperature
non-interacting dynamical polarization function, plasmon modes and electron
energy loss function of doped single layer gapped graphene within the random
phase approximation. We find that the interplay of linear energy band
dispersion, chirality, bandgap and temperature endow single layer gapped
graphene with strange polarizability behaviour which is a mixture of 2DEG,
single layer and bilayer graphene and as a result the plasmon spectrum also
manifests strikingly peculiar behaviour. The plasmon dispersion is observed to
be suppressed till temperatures up to ~0.5Tf, similar to the gapless graphene
case but beyond 0.5Tf a reversal in trend is seen in gapped graphene, for all
values of band gap. This behaviour is also corroborated by the density plots of
electron energy loss function. The opening of a small gap also generates a new
undamped plasmon mode which is found to disappear at high temperatures. The
plasmonic behaviour of gapped graphene is further found to be hugely influenced
by the substrate on which the gapped graphene sheet rests, which signifies the
need for a careful substrate selection in the making of desirable graphene
based plasmonics devices.
