▎ 摘 要
We have investigated the effects of in-plane and interplane nearest neighbor overlap integrals (s(0) and s'(1)) and the site energy difference (Delta) between atoms in two different sublattices in the same graphene layer on the electronic dispersion of bilayer graphene within tight binding model. We then extended the calculation to include the in-plane next nearest neighbor interactions (gamma(1), s(1)) and next to next nearest neighbor interactions (gamma(2), s(2)) for bilayer graphene bands. It is observed that s'(1) introduces further asymmetry in energy values of top conduction band and bottom valence band at the K point in addition to the asymmetry due to Delta. In general there is noticeable electron-hole asymmetry in the slope of the bands away from the K point, and also the changes in band widths due to s'(1) as well as the other in-plane coupling parameters. The density of states of bilayer graphene has also been calculated within the same model.