▎ 摘　　要

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 Gamma 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. (C) 2014 Elsevier Ltd. All rights reserved.