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Strain engineering of graphene through interaction with a patterned substrate offers the possibility of tailoring its electronic properties, but will require detailed understanding of how graphenes morphology is determined by the underlying substrate. However, previous experimental reports have drawn conflicting conclusions about the structure of graphene on SiO2. Here we show that high-resolution non-contact atomic force microscopy of SiO2 reveals roughness at the few-nm length scale unresolved in previous measurements, and scanning tunneling microscopy of graphene on SiO2 shows it to be slightly smoother than the supporting SiO2 substrate. Quantitative analysis of the competition between bending rigidity of the graphene and adhesion to the substrate explains the observed roughness of monolayer graphene on SiO2 as extrinsic, and provides a natural, intuitive description in terms of highly conformal adhesion. The analysis indicates that graphene adopts the conformation of the underlying substrate down to the smallest features with nearly 99% fidelity.
We have carried out scanning tunneling spectroscopy measurements on exfoliated monolayer graphene on SiO$_2$ to probe the correlation between its electronic and structural properties. Maps of the local density of states are characterized by electron
We report on infrared (IR) nanoscopy of 2D plasmon excitations of Dirac fermions in graphene. This is achieved by confining mid-IR radiation at the apex of a nanoscale tip: an approach yielding two orders of magnitude increase in the value of in-plan
We have measured the impact of atomic hydrogen adsorption on the electronic transport properties of graphene sheets as a function of hydrogen coverage and initial, pre-hydrogenation field-effect mobility. Our results are compatible with hydrogen adso
It is important for modern scanning microwave microscopes to overcome the effect of the surface roughness. Here, we report microwave conductivity imaging of the phase-separated iron chalcogenide K$_x$Fe$_y$Se$_2$ ($x=0.8$, $y=1.6$-$2$), in which elec
We have calculated the optical conductivity of a disorder-free single graphene sheet in the presence of spin-orbit coupling, using the Kubo formalism. Both intrinsic and structural-inversion-asymmetry induced types of spin splitting are considered wi