Gate-tunable bandgap in bilayer graphene

Abstract

The tight-binding model of bilayer graphene is used to find the gap between the conduction and valence bands, as a function of both the gate voltage and as the doping by donors or acceptors. The total Hartree energy is minimized and the equation for the gap is obtained. This equation for the ratio of the gap to the chemical potential is determined only by the screening constant. Thus the gap is strictly proportional to the gate voltage or the carrier concentration in the absence of donors or acceptors. In the opposite case, where the donors or acceptors are present, the gap demonstrates the asymmetrical behavior on the electron and hole sides of the gate bias. A comparison with experimental data obtained by Kuzmenko et al demonstrates the good agreement.

6 pages, 5 figures

References in corpus (7)

• Biased bilayer graphene: semiconductor with a gap tunable by electric field effect
• Asymmetry gap in the electronic band structure of bilayer graphene
• Determination of the electronic structure of bilayer graphene from infrared spectroscopy results
• Infrared spectroscopy of electronic bands in bilayer graphene
• Optical conductivity of bilayer graphene with and without an asymmetry gap
• Effect of electron-electron interactions on the conductivity of clean graphene
• Band structure asymmetry of bilayer graphene revealed by infrared spectroscopy

Cited by in corpus (4)

• Electrically Tunable Fine Structure of Negatively Charged Excitons in Gated Bilayer Graphene Quantum Dots
• Ultraviolet absorption spectrum of the half-filled bilayer graphene
• Second and third harmonics generation by coherent sub-THz radiation at induced Lifshitz transitions in gapped bilayer graphene
• High energy shift in the optical conductivity spectrum of the bilayer graphene