Optical conductivity renormalization of graphene on SrTiO$_{3}$ due to   resonant excitonic effects mediated by Ti 3\textit{d} orbitals
  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. 
Pranjal Kumar Gogoi, Paolo E. Trevisanutto, Ming Yang, Iman Santoso,   Teguh Citra Asmara, Aleksandrs Terentjevs, Fabio Dell...
cond-mat.str-el cond-mat.mtrl-sci