Graphene on incommensurate substrates: Trigonal warping and emerging Dirac cone replicas with halved group velocity

被引：73

作者：

Ortix, Carmine ^{[1
]}

Yang, Liping ^{[1
]}

van den Brink, Jeroen ^{[1
]}

机构：

[1] IFW Dresden, Inst Theoret Solid State Phys, D-01171 Dresden, Germany

来源：

PHYSICAL REVIEW B | 2012年 / 86卷 / 08期

关键词：

FERMIONS;

D O I：

10.1103/PhysRevB.86.081405

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The adhesion of graphene on slightly lattice-mismatched surfaces, for instance, of hexagonal boron nitride (hBN) or Ir(111), gives rise to a complex landscape of sublattice symmetry-breaking potentials for the Dirac fermions. Whereas a gap at the Dirac point opens for perfectly lattice-matched graphene on hBN, we show that the small lattice incommensurability prevents the opening of this gap and rather leads to a renormalized Dirac dispersion with a trigonal warping. This warping breaks the effective time-reversal symmetry in a single valley. On top of this an additional set of massless Dirac fermions is generated, which is characterized by a group velocity that is about half the one of pristine graphene.

引用

页数：5

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