Band gaps in graphene via periodic electrostatic gating

Abstract

Much attention has been focused on ways of rendering graphene semiconducting. We study periodically gated graphene in a tight-binding model and find that, contrary to predictions based on the Dirac equation, it is possible to open a band gap at the Fermi level using electrostatic gating of graphene. However, comparing to other methods of periodically modulating graphene, namely perforated graphene structures, we find that the resulting band gap is significantly smaller. We discuss the intricate dependence of the band gap on the magnitude of the gate potential as well as the exact geometry of the edge of the gate region. The role of the overlap of the eigenstates with the gate region is elucidated. Considering more realistic gate potentials, we find that introducing smoothing in the potential distribution, even over a range of little more than a single carbon atom, reduces the attainable band gap significantly.

9 pages, 9 figures

References in corpus (17)

• Electric Field Effect in Atomically Thin Carbon Films
• The electronic properties of graphene
• Energy Gaps in Graphene Nanoribbons
• Control of graphene's properties by reversible hydrogenation
• Chiral tunneling and the Klein paradox in graphene
• Graphane: a two-dimensional hydrocarbon
• Electronic States of Graphene Nanoribbons
• Andreev reflection and Klein tunneling in graphene
• Graphene Antidot Lattices - Designed Defects and Spin Qubits
• Magnetic confinement of massless Dirac fermions in graphene
• New Generation of Massless Dirac Fermions in Graphene under External Periodic Potentials
• Electronic properties of graphene antidot lattices
• Gaps tunable by electrostatic gates in strained graphene
• Character of electronic states in graphene antidot lattices: Flat bands and spatial localization
• Bound states in inhomogeneous magnetic field in graphene: a semiclassical approach
• Band structure and gaps of triangular graphene superlattices
• Spin qubits in antidot lattices

Cited by in corpus (1)

• Single-parameter quantum charge and spin pumping in armchair graphene nanoribbons