Energy-gap Opening and Quenching in Graphene under Periodic External Potentials

Abstract

In this paper, we investigated the effects of periodic external potentials on properties of charge carriers in graphene using both the first-principles method based on density functional theory (DFT) and a theoretical approach based on a generalized effective spinor Hamiltonian. DFT calculations were done in a modified Kohn-Sham procedure that includes effects of the periodic external potential. Unexpected energy band gap opening and quenching were predicted for the graphene superlattice with two symmetrical sublattices and those with two unsymmetrical sublattices, respectively. Theoretical analysis based on the spinor Hamiltonian showed that the correlations between pseudospins of Dirac fermions in graphene and the applied external potential, and the potential-induced intervalley scattering, play important roles in energy-gap opening and quenching.

References in corpus (8)

• Electric Field Effect in Atomically Thin Carbon Films
• The electronic properties of graphene
• Anisotropic behaviors of massless Dirac fermions in graphene under periodic potential
• Graphene Antidot Lattices - Designed Defects and Spin Qubits
• New Generation of Massless Dirac Fermions in Graphene under External Periodic Potentials
• Electron Beam Supercollimation in Graphene Superlattices
• Landau Levels and Quantum Hall Effect in Graphene Superlattices
• Analytical Approach to the Local Contact Potential Difference on (001) Ionic Surfaces: Implications for Kelvin Probe Force Microscopy

Cited by in corpus (3)

• Hofstadter butterflies and magnetically induced band gap quenching in graphene antidot lattices
• Band gaps in graphene via periodic electrostatic gating
• Massless Dirac Fermions in Graphene under an External Periodic Magnetic Field