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arXiv · cond-mat/0611635

Coulomb screening and collective excitations in a graphene bilayer

Xue-Feng Wang·Tapash Chakraborty
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Abstract

We have investigated the Coulomb screening properties and collective excitations in a graphene bilayer. The static screening effect is anisotropic and is much stronger in the undoped graphene bilayer than in a monolayer graphene [1]. The dynamic screening shows the properties of a Dirac gas in the low frequency and that of a Fermi gas in the high frequency. The transition from the Dirac to the Fermi gas is also observed in the plasmon spectrum. Finally, we find that an electron gas in a doped graphene bilayer has quite similar properties as those of a Fermi gas in materials containing two energy valleys.

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Xue-Feng Wang, Tapash Chakraborty. 2006-11-28. Coulomb screening and collective excitations in a graphene bilayer. https://doi.org/10.1103/physrevb.75.041404

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