Gap opening of single-layer graphene under the continuum model
arXiv:1106.0083 · doi:10.1016/j.physleta.2011.11.020
Abstract
Gap opening at the Dirac point of the single-layer graphene with periodic scalar and vector potentials has been theoretically investigated under the continuum model. The symmetry analysis indicates that the two-fold degeneracy at the Dirac point can be lifted when the potentials break both the chiral symmetry and the time-reversal symmetry. A gap equation at the Dirac point is obtained analytically with perturbation theory. It is shown that a mass term at the Dirac point would be generated by coupling of vector and scalar potentials. This gap equation could be considered as a criterion for gap opening at the Dirac point, which is confirmed by the numerical calculation. Furthermore, the bandgap from the gap equation agrees well with the exact result, when the applied potentials are weak.
It contains 14 page in text written by MS word 2007, and 4 figures
References in corpus (16)
- Electric Field Effect in Atomically Thin Carbon Films
- The electronic properties of graphene
- Two Dimensional Atomic Crystals
- Energy Band Gap Engineering of Graphene Nanoribbons
- Chiral tunneling and the Klein paradox in graphene
- Andreev reflection and Klein tunneling in graphene
- Graphene Antidot Lattices - Designed Defects and Spin Qubits
- New Generation of Massless Dirac Fermions in Graphene under External Periodic Potentials
- How perfect can graphene be?
- Multiple magnetic barriers in graphene
- Gaps tunable by electrostatic gates in strained graphene
- Single-layer and bilayer graphene superlattices: collimation, additional Dirac points and Dirac lines
- Finite difference method for transport properties of massless Dirac fermions
- Electronic and magnetic properties of superlattices of graphene/graphane nanoribbons with different edge hydrogenation
- Fate of Dirac Points in a Vortex Superlattice
- Energy-gap Opening and Quenching in Graphene under Periodic External Potentials