Localized Collective Excitations in Doped Graphene in Strong Magnetic Fields

Abstract

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 nu = 1, 2, 3, 4 of the lowest LL. We predict impurity absorption peaks above as well as below the cyclotron resonance. We show 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- magneto-absorption peaks having same energies, but active in different circular polarizations.

5 pages, 5 figures (only 3 captions). Included a more qualitative discussion of the results and method, in particular addressing the issue of screening. Paper lengthened and more references added

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Cited by in corpus (5)

• On the universal AC optical background in graphene
• Magnetoplasmons and SU(4) symmetry in graphene
• Symmetry Content and Observation of Charged Collective Excitations for Graphene in Strong Magnetic Fields
• Magnetoplasmons bound to short-range impurities in graphene: Symmetries and optics
• Localised Magneto-Optical Collective Excitations of Impure Graphene