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Visualizing broken symmetry states in the zeroth Landau level of the graphene quantum Hall system

ORAL

Abstract

In graphene, the combination of electron spin and two equivalent sublattice atoms results in a four-fold degeneracy of Landau levels. A number of competing quantum Hall isospin states inside the four-fold degenerate zeroth landau level of graphene have been suggested based on macroscopic transport measurements. Here we observe the broken symmetry states of the zeroth Landau level in graphene with Kelvin Probe Force Microscopy (KPFM) by using a millikelvin scanning probe microscope coupled with qPlus sensor. The field dependence of the energy difference between isospin states is suggestive of transitions between isospin configurations at certain magnetic field values. In addition, we show how the quantum Hall edge channels of zeroth Landau level spatially develop and disperse at the edge of Hall bar.

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Presenters

  • Sungmin Kim

    Physical Measurement Laboratory, National Institute of Standards and Technology

Authors

  • Sungmin Kim

    Physical Measurement Laboratory, National Institute of Standards and Technology

  • Daniel Walkup

    Physical Measurement Laboratory, National Institute of Standards and Technology, National Institute of Standards and Technology

  • Johannes Schwenk

    Laboratory of Nanostructure at Surfaces, Ecole Polytechnique Federale de Lausanne

  • Yihang Zeng

    Columbia University, Columbia Univ, Department of Physics, Columbia University

  • Fereshte Ghahari Kermani

    Department of Physics and Astronomy, George Mason University, National Institute of Standards and Technology

  • Son Le

    National Institute of Standards and Technology, Physical Measurement Laboratory, National Institute of Standards and Technology, NIST & Theiss Research, Theiss Research and The National Institute of Standards and Technology

  • Julian Berwanger

    Institute of Experimental and Applied Physics, University of Regensburg

  • Kenji Watanabe

    National Institute for Materials Science, Japan, National Institute for Material Science, National Institute for Materials Science, National Institute for Materials Science, Tsukuba, Research Center for Functional Materials, NIMS, nims, Advanced Materials Laboratory, National Institute for Materials Science, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, NIMS, National Institute for Material Science - Japan, NIMS Tsukuba, National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan., National Institute for Materials Science (NIMS), National Institute for Materials Science,Tsukuba, Ibaraki 305-0047, Japan, Advanced Materials Laboratory, NIMS, Japan, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Materials Science, National Institute for Materials Science, University of Tsukuba, National Institute for Materials Science, Tsukuba, Japan, National Institute for Material Science, Japan, National Institue for Material Science, Tsukuba, Advanced Materials Laboratory, NIMS, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba 305-0044, Japan, Advanced Matrials Lab, NIMS, National Institute for Material Science, Tsukuba, Japan, National institute for materials science, NIMS-Tsukuba, NIMS, Japan, National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan, NIRM, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan, NIMS Japan, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, Advanced Materials Laboratory, National Institute of Materials Science, Advanced Materials Laboratory, National Institute for Materials Science 1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science (Japan), Physics, NIMS, National Institute of Materials Science, Japan, National Institute of Materials Science (NIMS), National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan, NIMS - Tsukuba

  • Takashi Taniguchi

    National Institute for Materials Science, Japan, National Institute for Material Science, National Institute for Materials Science, National Institute for Materials Science, Tsukuba, Research Center for Functional Materials, NIMS, nims, Advanced Materials Laboratory, National Institute for Materials Science, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, NIMS, National Institute for Material Science - Japan, NIMS Tsukuba, National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan., National Institute for Materials Science (NIMS), National Institute for Materials Science,Tsukuba, Ibaraki 305-0047, Japan, Advanced Materials Laboratory, NIMS, Japan, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Materials Science, National Institute for Materials Science, University of Tsukuba, National Institute for Materials Science, Tsukuba, Japan, National Institue for Material Science, Tsukuba, Advanced Materials Laboratory, NIMS, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba 305-0044, Japan, Advanced Matrials Lab, NIMS, National Institute for Material Science, Tsukuba, Japan, National institute for materials science, NIMS-Tsukuba, NIMS, Japan, National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan, Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan, NIMS Japan, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, Advanced Materials Laboratory, National Institute of Materials Science, Advanced Materials Laboratory, National Institute for Materials Science 1-1 Namiki, Tsukuba, 305-0044, Japan, National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science (Japan), Physics, NIMS, National Institute of Materials Science, Japan, National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan, NIMS - Tsukuba

  • Franz J Giessibl

    Institute of Experimental and Applied Physics, University of Regensburg

  • Nikolai Zhitenev

    Physical Measurement Laboratory, National Institute of Standards and Technology, National Institute of Standards and Technology

  • Cory Dean

    Department of Physics, Columbia University, Columbia University, Columbia Univ, Physics, Columbia University

  • Joseph Stroscio

    Physical Measurement Laboratory, National Institute of Standards and Technology, National Institute of Standards and Technology