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Asymmetry gap in the electronic band structure of bilayer graphene

Edward McCann
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Abstract

A tight binding model is used to calculate the band structure of bilayer graphene in the presence of a potential difference between the layers that opens a gap $Δ$ between the conduction and valence bands. In particular, a self consistent Hartree approximation is used to describe imperfect screening of an external gate, employed primarily to control the density $n$ of electrons on the bilayer, resulting in a potential difference between the layers and a density dependent gap $Δ(n)$. We discuss the influence of a finite asymmetry gap $Δ(0)$ at zero excess density, caused by the screening of an additional transverse electric field, on observations of the quantum Hall effect.

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Edward McCann. 2006-11-02. Asymmetry gap in the electronic band structure of bilayer graphene. https://doi.org/10.1103/physrevb.74.161403

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