Article,
Energy levels of bilayer graphene quantum dots
PHYSICAL REVIEW B, (2015)
DOI: 10.1103/PhysRevB.92.115437
Abstract
Within a tight binding approach we investigate the energy levels of
hexagonal and triangular bilayer graphene (BLG) quantum dots (QDs) with
zigzag and armchair edges. We study AA- and AB-(Bernal) stacked BLG QDs
and obtain the energy levels in both the absence and the presence of a
perpendicular electric field (i.e., biased BLG QDs). Our results show
that the size dependence of the energy levels is different from that of
monolayer graphene QDs. The energy spectrum of AB-stacked BLG QDs with
zigzag edges exhibits edge states which spread out into the opened
energy gap in the presence of a perpendicular electric field. We found
that the behavior of these edges states is different for the hexagonal
and triangular geometries. In the case of AA-stacked BLG QDs, the
electron and hole energy levels cross each other in both cases of
armchair and zigzag edges as the dot size or the applied bias increases.
