• 文献标题:   Localized collective excitations in doped graphene in strong magnetic fields
  • 文献类型:   Article
  • 作  者:   FISCHER AM, DZYUBENKO AB, ROMER RA
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   1098-0121
  • 通讯作者地址:   Univ Warwick
  • 被引频次:   8
  • DOI:   10.1103/PhysRevB.80.165410
  • 出版年:   2009

▎ 摘  要

We consider collective excitations in graphene with filled Landau levels (LL's) in the presence of an external potential due to a single charged donor D+ or acceptor A(-) impurity. We show that localized collective modes split off the magnetoplasmon continuum and, in addition, quasibound states are formed within the continuum. A study of the evolution of the strengths and energies of magneto-optical transitions is performed for integer filling factors v=1,2,3,4 of the lowest LL. We predict impurity absorption peaks above as well as below the cyclotron resonance. We find that the single-particle electron-hole symmetry of graphene leads to a duality between the spectra of collective modes for the D+ and A(-). The duality shows up as a set of the D+ and A(-) magnetoabsorption peaks having the same energies but active in different circular polarizations.