Gapless spin-1 neutral collective mode branch for graphite.

نویسندگان

  • G Baskaran
  • S A Jafari
چکیده

Using the standard tight binding model of 2D graphite with short range electron repulsion, we predict a gapless spin-1, neutral collective mode branch below the particle-hole continuum with energy vanishing linearly with momenta at the Gamma and K points in the Brillouin zone. This spin-1 mode has a wide energy dispersion, 0 to approximately 2 eV, and is not Landau damped. The "Dirac cone spectrum" of electrons at the chemical potential of graphite generates our collective mode, so we call this "spin-1 zero sound" of the "Dirac sea." Epithermal neutron scattering experiments and spin polarized electron energy loss spectroscopy can be used to confirm and study our collective mode.

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عنوان ژورنال:
  • Physical review letters

دوره 92 19  شماره 

صفحات  -

تاریخ انتشار 2002