SPM measurements of graphene corrugation and spatial correlation

ORAL

Abstract

In order to determine the effect of graphene corrugation on electronic transport, it is most important to know the spatial correlation properties of the corrugated graphene structure. In spite of much experimental effort, there is still contentious debate about the structure of graphene, both in supported and suspended geometries. It has frequently been asserted that a graphene monolayer exfoliated onto a SiO2 substrate may display ``intrinsic'' corrugation -- rippled structure which is not derived from the topography of the underlying substrate. Here, we report recent UHV NC-AFM and STM results which show that anomalous corrugation may be observed due to local interaction between the tip and the graphene monolayer. Our results show that non-perturbative NC-AFM measurement reveals a graphene topography which is as smooth as the underlying SiO2, with height-height correlation exponent 2H = 1. STM measurement of graphene, due to uncontrolled tip-sample forces, may exhibit anomalous corrugation depending on tip condition.

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Authors

  • William G. Cullen

    University of Maryland, Physics Department, University of Maryland, College Park, MD 20742, Materials Research Science and Engineering Center, Center for Nanophysics and Advanced Materials, Dept of Physics, Univ. of Maryland, College Park, MD, University of Maryland College Park, Dept. of Physics, U. of Maryland - College Park

  • Jian-Hao Chen

    University of Maryland, College Park, Department of Physics and University of Maryland Materials Research Science and Engineering Center, University of Maryland, College Park, MD 20742, Dept of Physics, Center for Nanophysics and Advanced Materials, and Materials Research Science and Engineering Center, Univ. of Maryland, College Park, University of Maryland, Department of Physics, University of Maryland, Materials Research Science and Engineering Center, Center for Nanophysics and Advanced Materials, Dept of Physics, Univ. of Maryland, College Park, MD

  • Masa Ishigami

    University of Central Florida

  • Ellen Williams

    University of Maryland, College Park, Department of Physics and University of Maryland Materials Research Science and Engineering Center, University of Maryland, College Park, MD 20742, University of Maryland, LPS, CNAM, and the DOP, UM, Physics Department, University of Maryland, College Park, MD 20742, Materials Research Science and Engineering Center, Center for Nanophysics and Advanced Materials, Dept of Physics, Univ. of Maryland, College Park, MD, University of Maryland College Park, Dept. of Physics, U. of Maryland - College Park, Department of Physics and Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742-4111, USA

  • Michael Fuhrer

    University of Maryland, Department of Physics and Center for Nanophysics and Advanced Materials, University of Maryland College Park, Department of Physics and Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742, USA, Materials Research Science and Engineering Center, Center for Nanophysics and Advanced Materials, Dept of Physics, Univ. of Maryland, College Park, MD, Materials Research Science and Engineering Center and Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, Department of Physics and Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742-4111, USA