Tunneling Magneto-Conductance Oscillations in Epitaxial Graphene

ORAL

Abstract

Scanning tunneling microscopy (STM) and spectroscopy (STS) at a temperature of 4 K are used to study the electronic properties of epitaxial graphene on SiC in a magnetic field applied perpendicular to the graphene plane. While changing the magnetic field we observe oscillations in the tunneling conductance, dI/dV (tunneling magneto-conductance oscillations, or TMCO). These are similar to Shubnikov-de Haas oscillations of magnetoresistance, but differ in important aspects. Magnetic field scans acquired at multiple tunneling injection energies allow us to create a density-of-states contour map as a function of both in energy and magnetic field. The data are well-described by the monolayer-graphene density of states, with small additional features that may indicate coherent effects. This work was supported in part by NSF, NRI-INDEX, and the W. M. Keck Foundation.

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Authors

  • Kevin D. Kubista

    Georgia Tech, Georgia Institute of Technology

  • David L. Miller

    Georgia Tech, Georgia Institute of Technology

  • Ming Ruan

    Georgia Institute of Technology

  • Milind Purohit

    Univ of South Carolina, Benedict College, Sc 29204, Univ. South Carolina, Benedict College, Univ South Carolina, GA Tech, Central Microscopy Research Facility, University of Iowa, Iowa City, Iowa 52242, USA, Department of Chemistry, University of Sri Jayewardenepura, Nugegoda, Sri Lanka, Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303, USA, Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, Department of Physics, University of Alabama at Birmingham, Birmingham, AL 35294, College of William \& Mary, Harvard University, Benedict College, SC 29204, Massachusetts Institute of Technology, University of Applied Science, Bielefeld, Germany, Francis Marion University, Physics Dept., Emory University, Emory University, Formerly Emory University, currently UCLA, Physics Department, Georgia State University, Univ. of Georgia, Dept. of Chemistry, Universidad Nacional de Quilmes, Argentina, Pr, Dr, Derpartment of Physics, Florida A\&M University, Tallahassee, FL-32307, Department of Physics, Emory University, Georgia Institute of Technology, Naval Research Laboratory, University of Alabama, Tsinghua University, Lawrence Berkeley National Laboratory, Vanderbilt University, Jagellonian Univ., Univ. of Bonn, North Carolina A\&T State Univ., North Carolina Central Univ., Duke Univ. and TUNL, Georgia State University, Dept of Physics, Emory University, Cell Biology Department, Emory University, Physics Department, Emory University, University of South Carolina

  • Phillip N. First

    Georgia Institute of Technology

  • Gregory M. Rutter

    Center for Nanoscale Science and Technology, NIST

  • Joseph A. Stroscio

    Center for Nanoscale Science and Technology, NIST