• 文献标题:   Finite temperature dynamical polarization and plasmons in gapped graphene
  • 文献类型:   Article
  • 作  者:   PATEL DK, ASHRAF SSZ, SHARMA AC
  • 作者关键词:   band gap, electron energy loss spectroscopy, graphene, plasmon, polarization function, single particle excitation
  • 出版物名称:   PHYSICA STATUS SOLIDI BBASIC SOLID STATE PHYSICS
  • ISSN:   0370-1972 EI 1521-3951
  • 通讯作者地址:   Aligarh Muslim Univ
  • 被引频次:   4
  • DOI:   10.1002/pssb.201451682
  • 出版年:   2015

▎ 摘  要

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 (SLGG) within the random phase approximation. We find that the interplay of linear energy band dispersion, chirality, bandgap, and temperature endow SLGG with strange polarizability behavior, which is a mixture of 2DEG, single layer and bilayer graphene and as a result the plasmon spectrum also manifests strikingly peculiar behavior. The plasmon dispersion is observed to be suppressed till temperatures up to similar to 0.5T(f), similar to the gapless graphene case but beyond 0.5T(f) a reversal in trend is seen in gapped graphene, for all values of band gap. This behavior 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 behavior 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. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim