Controlled formation of an isolated miniband in bilayer graphene on an almost commensurate $\sqrt{3}\times \sqrt{3}$ substrate

Abstract

We investigate theoretically the interplay between the effects of a perpendicular electric field and incommensurability at the interface on the electronic properties of a heterostructure of bilayer graphene and a semiconducting substrate with a unit cell almost three times larger then that of graphene. It is known that the former introduces an asymmetry in the distribution of the electronic wave function between the layers and opens a band gap in the electronic spectrum. The latter generates a long wavelength periodic moiré perturbation of graphene electrons which couples states in inequivalent graphene Brillouin zone corners and leads to the formation of minibands. We show that, depending on the details of the moiré perturbation, the miniband structure can be tuned from that with a single band gap at the neutrality point and over-lapping minibands on the conduction/valence band side to a situation where a single narrow miniband is separated by gaps from the rest of the spectrum.

7 pages, 3 figures

References in corpus (13)

• Biased bilayer graphene: semiconductor with a gap tunable by electric field effect
• STM Spectroscopy of ultra-flat graphene on hexagonal boron nitride
• Asymmetry gap in the electronic band structure of bilayer graphene
• Detecting Topological Currents in Graphene Superlattices
• Infrared spectroscopy of Landau levels in graphene
• Dirac Cones and Minigaps for Graphene on Ir(111)
• New Generation of Massless Dirac Fermions in Graphene under External Periodic Potentials
• Electrons and phonons in single layers of hexagonal indium chalcogenides from ab initio calculations
• Unit cell of graphene on Ru(0001): a 25 x 25 supercell with 1250 carbon atoms
• Energy gap opening in submonolayer lithium on graphene: Local density functional and tight-binding calculations
• Transport in superlattices on single layer graphene
• Single-Valley Engineering in Graphene Superlattices
• Kekule' textures, pseudo-spin one Dirac cones and quadratic band crossings in a graphene-hexagonal indium chalcogenide bilayer