Gatetunable bandgap in bilayer graphene
Abstract
The tightbinding 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 the doping level by donors or acceptors. The total Hartree energy is minimized and an 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. Therefore, the gap is strictly proportional to the gate voltage or the carrier concentration in the absence of donors or acceptors. But in the case where the donors or acceptors are present, the gap demonstrates an asymmetric behavior on the electron and hole sides of the gate bias. A comparison with experimental data obtained by Kuzmenko et al. demonstrates a good agreement.
 Publication:

Soviet Journal of Experimental and Theoretical Physics
 Pub Date:
 February 2010
 DOI:
 10.1134/S1063776110020159
 arXiv:
 arXiv:0908.3371
 Bibcode:
 2010JETP..110..319F
 Keywords:

 Condensed Matter  Mesoscale and Nanoscale Physics;
 Condensed Matter  Materials Science
 EPrint:
 6 pages, 5 figures