Interaction-induced metallic state in graphene on hexagonal boron nitride
arXiv:1611.00908 · doi:10.1103/PhysRevB.94.195103
Abstract
The Coulomb interaction is widely known to enhance the effective mass of interacting particles and therefore tends to favor a localized state at commensurate filling. Here, we will show that, in contrast to this consensus, in a van der Waals heterostructure consisting of graphene and hexagon boron nitride (h-BN), the onsite Coulomb repulsion will at first destroy the localized state. This is due to the fact that the onsite Coulomb repulsion tends to suppress the asymmetry between neighboring carbons induced by h-BN substrate. We corroborate this surprising phenomenon by solving a tight-binding model with onsite Coulomb repulsion treated within coherent potential approximation, where hopping parameters are derived from density functional theory calculations based on the graphene/h-BN heterostructure. Our results indicate that both gapless and gapped states observed experimentally in graphene/h-BN heterostructures can be understood after a realistic value of the onsite Coulomb repulsion as well as different interlayer distances are taken into account. Finally, we propose ways to enhance the gapped state which is essential for potential application of graphene to next-generation electronics. Furthermore, we argue that band gap suppressed by many-body effect should happen in other van der Waals heterostructures.
9 pages, 8 figures
References in corpus (17)
- Energy Band Gap Engineering of Graphene Nanoribbons
- Control of graphene's properties by reversible hydrogenation
- Biased bilayer graphene: semiconductor with a gap tunable by electric field effect
- STM Spectroscopy of ultra-flat graphene on hexagonal boron nitride
- Multicomponent fractional quantum Hall effect in graphene
- Origin of band gaps in graphene on hexagonal boron nitride
- Absence of a Spin Liquid Phase in the Hubbard Model on the Honeycomb Lattice
- Energy gap tuning in graphene on hexagonal boron nitride bilayer system
- Fermionic quantum criticality in honeycomb and -flux Hubbard models: Finite-size scaling of renormalization-group-invariant observables from quantum Monte Carlo
- Zero Energy Modes and Gate-Tunable Gap in Graphene on hexagonal Boron Nitride
- Observation of an intrinsic bandgap and Landau level renormalization in graphene/boron-nitride heterostructures
- Moir{é} patterns as a probe of interplanar interactions: graphene on h-BN
- Spontaneous Strains and Gap in Graphene on Boron Nitride
- Interacting Dirac Fermions on Honeycomb Lattice
- Disappearance of the Dirac cone in silicene due to the presence of an electric field
- Inclusion of intersite spatial correlations in the alloy analogy approach to the half-filled ionic Hubbard model
- Dynamical nonlocal coherent-potential approximation for itinerant electron magnetism