Substrate effects on quasiparticles and excitons in graphene nanoflakes
arXiv:1308.4790 · doi:10.1063/1.4823829
Abstract
The effects of substrate on electronic and optical properties of triangular and hexagonal graphene nanoflakes with armchair edges are investigated by using a configuration interaction approach beyond double excitation scheme. The quasiparticle correction to the energy gap and exciton binding energy are found to be dominated by the long-range Coulomb interactions and exhibit similar dependence on the dielectric constant of the substrate, which leads to a cancellation of their contributions to the optical gap. As a result, the optical gaps are shown to be insensitive to the dielectric environment and unexpectedly close to the single-particle gaps.
4 pages, 4 figures
References in corpus (16)
- Electric Field Effect in Atomically Thin Carbon Films
- Energy Gaps in Graphene Nanoribbons
- Graphene photodetectors for high-speed optical communications
- Atomic Structure of Graphene on SiO2
- Electron-Electron Interactions in Graphene: Current Status and Perspectives
- Strength of effective Coulomb interactions in graphene and graphite
- First direct observation of Dirac fermions in graphite
- Tuning the effective fine structure constant in graphene: opposing effects of dielectric screening on short- and long-range potential scattering
- Many-body interactions in quasi-freestanding graphene
- Excitonic absorption in gate controlled graphene quantum dots
- Electron-Electron Interactions on the Edge States of Graphene: A Many Body Configuration Interaction Study
- Exciton formation in graphene bilayer
- Epitaxial growth mechanisms of graphene and effects of substrates
- Variational approach to the excitonic phase transition in graphene
- Finite-size version of the excitonic instability in graphene quantum dots
- Excitonic Effects in the Optical Spectra of Graphene Nanoribbons