The Effect of a Lattice Defect on Graphene Landau Levels: A Scanning Tunneling Spectroscopy Study

ORAL

Abstract

We present tunneling differential conductance (dI/dV) spectra and 2D conductance maps acquired over both N- and P-type defects in magnetic fields up to 8 T. The measurements were performed on multilayer epitaxial graphene using scanning tunneling microscopy and spectroscopy at 4 K under ultra high vacuum conditions. Landau levels are found to follow the local potential (determined independently at near-zero magnetic field) until an instability is reached close to the defect. Spectral shifts at high magnetic field are modeled using the low-field-derived potential maps. The source of the tunnel instability will be discussed.

*Work supported in part by NSF and NRI-INDEX.

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Authors

  • Kevin D. Kubista

    • Georgia Institute of Technology

  • David L. Miller

    • Georgia Institute of Technology

  • Ming Ruan

    • Georgia Institute of Technology

  • Walt A. de Heer

    • Georgia Institute of Technology

  • Phillip First

    • Georgia Institute of Technology

  • Gregory Rutter

    • Center for Nanoscale Science and Technology, NIST
    • National Institute of Standards and Technology

  • Joseph A. Stroscio

    • Center for Nanoscale Science and Technology, NIST