An effective method of tuning conducting properties: First-principles studies on electronic structures of graphene nanomeshes

Based on detailed first-principles investigations of the hexagonal antidot patterned graphene nanomeshes, we have studied the mechanisms of the conducting property modification of graphene. The band-folding analysis shows that the (3n,3m) (n and m are integers) superlattice would have fourfold degeneracy at Г point. An effective method by removing this fourfold degeneracy, such as regularly arranging antidots to make the (3n,3m) nanomesh, is proposed to open a sizable bandgap no matter whether the sublattice equivalence keeps or not. In the nanomeshes patterned with the magnetic antidots, the antiferromagnetic coupling adds a quantum parameter to break the sublattice equivalence, resulting in the bandgap opening at the twofold degenerate K (K′) point. Our studies also show that the gap width could be tuned by controlling the antidot density. These results could facilitate the fascinating applications of graphene in the next-generation nanoelectronics.