Anisotropy of $\pi$-plasmon Dispersion Relation of AA-stacked Graphite

ORAL

Abstract

The dispersion relation of optical $\pi$-plasmons of simple hexagonal intrinsic graphite was calculated within the self-consistent-field approximation. The plasmon frequency $\omega_p$ is determined as functions of the wave vector $\textbf{q}_\parallel$ along the hexagonal plane in the Brillouin zone and its perpendicular component $q_z$. These plasmons are isotropic within the plane in the long wavelength limit. As the in-plane wave vector is increased, the plasmon frequency strongly depends on its magnitude and direction ($\phi$). Our results reveal that interlayer interaction could enhance anisotropy of in-plane $\pi$-plasmons. The group velocity for plasmon propagation along the perpendicular direction may be positive or negative depending on the choice of in-plane wave vector.

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Authors

  • C.W. Chiu

    • Department of Physics, National Cheng Kung University, Tainan 710, Taiwan

  • F.L. Shyu

    • Department of Physics, R.O.C. Military Academy, Kaohsiung 830, Taiwan

  • M.F. Lin

    • Department of Physics, National Cheng Kung University, Tainan 710, Taiwan

  • Godfrey Gumbs

    • Department of Physics and Astronomy, Hunter College at the City University of New York, 695 Park Avenue New York, NY 10065 USA

  • Oleksiy Roslyak

    • Department of Physics and Astronomy, Hunter College at the City University of New York, 695 Park Avenue New York, NY 10065, USA
    • Department of Physics and Astronomy, Hunter College of the City University of New York, 695 Park Avenue, New York, NY 10065 USA
    • Department of Physics and Astronomy, Hunter College at the City University of New York, 695 Park Avenue New York, NY 10065 USA
    • Hunter College, City University of New York
    • Department of Physics and Astronomy, Hunter College, City University of New York,695 Park Avenue, New York, NY 10065, USA
    • Physics \& Astronomy Department, Hunter College, CUNY