Graphene on SrTiO3

We study carrier transport through graphene on SrTiO3 substrates by considering relative contributions of Coulomb and resonant impurity scattering to graphene resistivity. We establish that charged impurity scattering must dominate graphene transport as the charge neutrality point is approached by lowering the carrier density, and in the higher density regime away from the neutrality point a dual model including both charged impurities and resonant defects gives an excellent description of graphene transport on SrTiO3 substrates. We further establish that the non-universal high-density behavior of σ(n)σ(n) in different graphene samples on various substrates arises from the competition among different scattering mechanisms, and it is in principle entirely possible for graphene transport to be dominated by qualitatively different scattering mechanisms at high and low carrier densities.

► A dual model including both charged impurities and resonant defects.
► Charged impurity dominates graphene transport near the Dirac point.
► Different scattering mechanisms dominate high and low-density graphene transport.