• 文献标题:   Transport gap in vertical devices made of incommensurately misoriented graphene layers
  • 文献类型:   Article
  • 作  者:   NGUYEN VH, DOLLFUS P
  • 作者关键词:   energy gap, graphene, tight binding approach
  • 出版物名称:   JOURNAL OF PHYSICS DAPPLIED PHYSICS
  • ISSN:   0022-3727 EI 1361-6463
  • 通讯作者地址:   Univ Paris Saclay
  • 被引频次:   1
  • DOI:   10.1088/0022-3727/49/4/045306
  • 出版年:   2016

▎ 摘  要

By means of atomistic tight-binding calculations, we investigate the transport properties of vertical devices made of two incommensurately misoriented graphene layers. For a given transport direction ( Ox-axis), we define two classes of rotated graphene lattice distinguished by difference in lattice symmetry and, hence, in Brillouin zone. In particular, these two classes correspond to two different cases where the position of their Dirac cones in the k(y)-axis is determined differently, i.e. K-y' = K-y = 0 or K-y'= -K-y = 2 pi/3L(y) (L-y is the periodic length along the Oy axis). As a consequence, in devices made of two layers of different lattice classes, the misalignment of Dirac cones between the left and right graphene sections opens a finite energy-gap of conductance that can reach a few hundreds of meV. We also show that strain engineering can be used to further enlarge the transport gap and to diminish the sensitivity of the gap on the twist angle and on the commensurateness of the layer stack.