Is Graphene a Fermi Liquid?

ORAL

Abstract

In this talk, we answer the question posed in the title above by considering theoretically the electron-electron interaction induced many-body effects in undoped (`intrinsic') and doped (`extrinsic') 2D graphene layers. We find that (1) intrinsic graphene is a \textit{marginal} Fermi liquid with the imaginary part of the self-energy, $\mathrm{Im}\Sigma(\omega)$, going as linear in energy $\omega$ for small $\omega$, implying that the quasiparticle spectral weight vanishes at the Dirac point as $(\mathrm{ln}\omega)^{-1}$; and, (2) extrinsic graphene is a well-defined Fermi liquid with $\mathrm{Im}\Sigma(\omega)\sim \omega^2\mathrm{ln}\omega$ near the Fermi surface similar to 2D carrier systems with parabolic energy dispersion. We provide analytical and numerical results for quasiparticle renormalization in graphene, concluding that all experimental graphene systems are ordinary 2D Fermi liquids since any doping automatically induces generic Fermi liquid behavior.

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Authors

  • Wang-Kong Tse

    Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, University of Maryland

  • Sankar Das Sarma

    Condensed Matter Theory Center, Physics Department, University of Maryland, Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742, USA, Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, MD 20742, University of Maryland, Condensed Matter Theory Center, University of Maryland, College Park, MD 20742-4111, USA, University of Maryland, College Park, CMTC, Department of Physics, University of Maryland, College Park, MD 20742, CMTC, Department of Physics, UMD, Maryland, Condensed Matter Theory Center, University of Maryland

  • Euyheon Hwang

    University of Maryland