Optical conductivity renormalization of graphene on SrTiO${}_3$ due to resonant excitonic effects mediated by Ti 3\textit{d} orbitals

Abstract

We present evidence of a drastic renormalization of the optical conductivity of graphene on SrTiO${}_3$ resulting in almost full transparency in the ultraviolet region. These findings are attributed to resonant excitonic effects further supported by \emph{ab initio} Bethe-Salpeter equation and density functional theory calculations. The ($\pi$,$\pi$*)-orbitals of graphene and Ti-3\textit{d} $t_{2g}$ orbitals of SrTiO${}_3$ are strongly hybridized and the interactions of electron-hole states residing in those orbitals play dominant role in the graphene optical conductivity. These interactions are present much below the optical band gap of bulk SrTiO${}_3$. These results open a possibility of manipulating interaction strengths in graphene via \textit {d}-orbitals which could be crucial for optical applications.

arXiv comment9 pages, 11 figures, Phys. Rev. B (accepted)

References in corpus (26)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• The electronic properties of graphene
• The Raman Fingerprint of Graphene
• Universal Dynamic Conductivity and Quantized Visible Opacity of Suspended Graphene
• 30 inch Roll-Based Production of High-Quality Graphene Films for Flexible Transparent Electrodes
• Electron-Electron Interactions in Graphene: Current Status and Perspectives
• Observation of the Fractional Quantum Hall Effect in Graphene
• BerkeleyGW: A Massively Parallel Computer Package for the Calculation of the Quasiparticle and Optical Properties of Materials and Nanostructures
• Fractional quantum Hall effect and insulating phase of Dirac electrons in graphene
• Hubbard-corrected DFT energy functionals: the LDA+U description of correlated systems
• Kramers-Kronig constrained variational analysis of optical spectra
• Dirac cones reshaped by interaction effects in suspended graphene
• Excitonic Effects on the Optical Response of Graphene and Bilayer Graphene
• Spectroscopic ellipsometry of graphene and an exciton-shifted van Hove peak in absorption
• Strength of effective Coulomb interactions in graphene and graphite
• Seeing many-body effects in single- and few-layer graphene: Observation of two-dimensional saddle-point excitons
• Tuning the effective fine structure constant in graphene: opposing effects of dielectric screening on short- and long-range potential scattering
• Lattice relaxation, electronic screening, and spin and orbital phase diagram of LaTiO${}_3$/SrTiO${}_3$ superlattices
• Excitonic Fano Resonance in Freestanding Graphene
• High-energy excitonic effects in graphite and graphene
• Tuning many-body interactions in graphene: The effects of doping on excitons and carrier lifetimes
• Excitonic effects in the optical conductivity of gated graphene
• Mechanisms of charge transfer and redistribution in LaAlO3/SrTiO3 revealed by high-energy optical conductivity
• Direct observation of room temperature high-energy resonant excitonic effects in graphene
• Tunable optical absorption and interactions in graphene via oxygen plasma
• Optical conductivity study of screening of many-body effects in graphene interfaces

Cited by in corpus (4)

• Synergetic Behavior in 2D Layered Material/Complex Oxide Heterostructures
• Enhancing charge-density-wave order in 1T-TiSe2 nanosheet by encapsulation with hexagonal Boron Nitride
• Optical Hall effect in strained graphene
• Exciton dissociation in two-dimensional transition metal dichalcogenides: Excited states and substrate effects