Optical and transport gaps in gated bilayer graphene

Abstract

We discuss the effect of disorder on the band gap measured in bilayer graphene in optical and transport experiments. By calculating the optical conductivity and density of states using a microscopic model in the presence of disorder, we demonstrate that the gap associated with transport experiments is smaller than that associated with optical experiments. Intrinsic bilayer graphene has an optical conductivity in which the energy of the peaks associated with the interband transition are very robust against disorder and thus provide an estimate of the band gap. In contrast, extraction of the band gap from the optical conductivity of extrinsic bilayer graphene is almost impossible for significant levels of disorder due to the ambiguity of the transition peaks. The density of states contains an upper bound on the gap measured in transport experiments, and disorder has the effect of reducing this gap which explains why these experiments have so far been unable to replicate the large band gaps seen in optical measurements.

5 pages, 5 figures, RevTeX. Published version

References in corpus (23)

• The electronic properties of graphene
• Boron nitride substrates for high-quality graphene electronics
• Electronic transport in two dimensional graphene
• Gate-induced insulating state in bilayer graphene devices
• Electronic Properties of Disordered Two-Dimensional Carbon
• Asymmetry gap in the electronic band structure of bilayer graphene
• A self-consistent theory for graphene transport
• Graphene field-effect-transistors with high on/off current ratio and large transport band gap at room temperature
• Properties of Graphene: A Theoretical Perspective
• Observation of an Electric-Field Induced Band Gap in Bilayer Graphene by Infrared Spectroscopy
• Ab Initio Theory of Gate Induced Gaps in Graphene Bilayers
• Electronic Transport in Dual-gated Bilayer Graphene at Large Displacement Fields
• Infrared spectroscopy of electronic bands in bilayer graphene
• Theory of carrier transport in bilayer graphene
• Conductivity of suspended and non-suspended graphene at finite gate voltage
• Impurities in a Biased Graphene Bilayer
• Charged impurity scattering in bilayer graphene
• Transport in gapped bilayer graphene: the role of potential fluctuations
• Origin of Universal Optical Conductivity and Optical Stacking Sequence Identification in Multilayer Graphene
• Charge transport in dual gated bilayer graphene with Corbino geometry
• Conductivity of graphene on boron nitride substrates
• Disorder-induced tail states in a gapped bilayer graphene
• Spectral and optical properties of doped graphene with charged impurities in the self-consistent Born approximation

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