AVS 61st International Symposium & Exhibition
    2D Materials Focus Topic Thursday Sessions
       Session 2D+EM+MI+MN+NS+SS+TF-ThA

Paper 2D+EM+MI+MN+NS+SS+TF-ThA4
Tip-induced Potential Confinement on Graphene in Scanning Tunneling Microscopy Measurement

Thursday, November 13, 2014, 3:20 pm, Room 310

Session: Novel Quantum Phenomena in 2D Materials 
Presenter: Yue Zhao, NIST/CNST
Authors: Y. Zhao, NIST/CNST
J. Chae, NIST/CNST
J.E. Wyrick, NIST/CNST
F.D. Natterer, Ecole Polytechnique Fédérale de Lausanne (EPFL), France
S. Jung, Korea Research Institute of Standards and Science (KRISS)
A.F. Young, Columbia University
C.R. Dean, Columbia University
L. Wang, Columbia University
Y. Gao, Columbia University
J.N. Rodrigues, Graphene Research Centre, NUS, Singapore
K. Watanabe, National Institute for Materials Science (NIMS), Japan
T. Taniguchi, National Institute for Materials Science (NIMS), Japan
S. Adam, Graphene Research Centre, NUS, Singapore
J.C. Hone, Columbia University
K. Shepard, Columbia University
P. Kim, Columbia University
N.B. Zhitenev, NIST/CNST
J.A. Stroscio, NIST/CNST
Correspondent: Click to Email
Graphene is a two-dimensional-electron-gas(2DEG) system with exposed surface, which allows scanning tunneling microscopy(STM) to investigate the electron-electron interaction associated with the Dirac nature on a local scale, with a variety of tuning knobs, such as carrier density, spatially varying disorder potential, and applied magnetic field. However, the electron-electron interaction in graphene is sensitive to the disorder details. Moreover, tip induced potential confinement can significantly complicate the interpretation of STM experiment. Utilizing a high mobility graphene device with low residual disorder, we can minimize the effect of local potential fluctuation, to better understand the role tip-induced potential plays in the measurement. We observed the emergency of large spectra gaps, modification to graphene Landau levels (LLs), and quantum dots with changing size due to the spatially inhomogeneous tip gating.