Edge channels of broken-symmetry quantum Hall states in graphene visualized by atomic force microscopy.

Autor: Kim S; Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.; Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA., Schwenk J; Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.; Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA., Walkup D; Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.; Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA., Zeng Y; Department of Physics, Columbia University, New York, NY, USA., Ghahari F; Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.; Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA., Le ST; Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.; Theiss Research, La Jolla, CA, USA., Slot MR; Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.; Department of Physics, Georgetown University, Washington, DC, USA., Berwanger J; Institute of Experimental and Applied Physics, University of Regensburg, Regensburg, Germany., Blankenship SR; Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA., Watanabe K; Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan., Taniguchi T; International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki, Japan., Giessibl FJ; Institute of Experimental and Applied Physics, University of Regensburg, Regensburg, Germany., Zhitenev NB; Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA., Dean CR; Department of Physics, Columbia University, New York, NY, USA. cdean@phys.columbia.edu., Stroscio JA; Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA. joseph.stroscio@nist.gov.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2021 May 14; Vol. 12 (1), pp. 2852. Date of Electronic Publication: 2021 May 14.
DOI: 10.1038/s41467-021-22886-7
Abstrakt: The quantum Hall (QH) effect, a topologically non-trivial quantum phase, expanded the concept of topological order in physics bringing into focus the intimate relation between the "bulk" topology and the edge states. The QH effect in graphene is distinguished by its four-fold degenerate zero energy Landau level (zLL), where the symmetry is broken by electron interactions on top of lattice-scale potentials. However, the broken-symmetry edge states have eluded spatial measurements. In this article, we spatially map the quantum Hall broken-symmetry edge states comprising the graphene zLL at integer filling factors of [Formula: see text] across the quantum Hall edge boundary using high-resolution atomic force microscopy (AFM) and show a gapped ground state proceeding from the bulk through to the QH edge boundary. Measurements of the chemical potential resolve the energies of the four-fold degenerate zLL as a function of magnetic field and show the interplay of the moiré superlattice potential of the graphene/boron nitride system and spin/valley symmetry-breaking effects in large magnetic fields.
Databáze: MEDLINE
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