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Topological surface state of Kondo insulator YbB<sub>12</sub>

ORAL

Abstract

YbB12 is a Kondo insulator which is theoretically predicted to host metallic surface states arising from the nontrivial band structure. Recent observation of quantum oscillations (QOs) in YbB12 arouses great interest since it may indicate a Fermi surface in an insulator phase. The most important subject is to clarify whether the QOs arise from insulating bulk or metallic surface. Here we fabricated micro-devices of YbB12 using focused ion beam technique and measured transport properties in high fields. All of the samples fabricated by FIB and mechanical polishing exhibit resistivity plateaus at low temperatures and residual resistivity decreases linearly as a function of thickness. These results provide evidence of 2D surface conduction in YbB12. We also find the device shows positive and quasi-linear H-dependent magnetoresistance, which is attributed to the anti-weak localization of the surface electrons with spin-momentum locking. No discernible QOs are observed in this device, suggesting the QOs in single crystals arise from insulating 3D bulk.

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Presenters

  • Yuki Sato

    Department of Physics, Kyoto University, Dept. Phys., Kyoto Univ., Kyoto Univ, Physics, Kyoto University

Authors

  • Yuki Sato

    Department of Physics, Kyoto University, Dept. Phys., Kyoto Univ., Kyoto Univ, Physics, Kyoto University

  • Shigeru Kasahara

    Department of Physics, Kyoto University, Dept. Phys., Kyoto Univ., Kyoto Univ, Physics, Kyoto University, Kyoto University

  • Yuichi Kasahara

    Department of Physics, Kyoto University, Department of Physics, Kyoto Univ, Physics, Kyoto University

  • Ziji Xiang

    Univ of Michigan - Ann Arbor, Department of Physics, University of Michigan, University of Michigan

  • Colin B Tinsman

    Univ of Michigan - Ann Arbor, Department of Physics, University of Michigan, University of Michigan

  • Lu Chen

    Univ of Michigan - Ann Arbor, Department of Physics, University of Michigan, University of Michigan

  • Lu Li

    Univ of Michigan - Ann Arbor, Department of Physics, University of Michigan, Physics, University of Michigan, University of Michigan

  • Takasada Shibauchi

    Advanced Materials Science, University of Tokyo, Univ of Tokyo-Kashiwanoha, Department of Advanced Materials Science, University of Tokyo, Univ of Tokyo, Dept. Adv. Mat. Sci., Univ. Tokyo, Univ. of Tokyo, Department of Advanced Materials Science, The University of Tokyo, Department of Advanced Material Science, University of Tokyo

  • Fumitoshi Iga

    College of Science, Ibaraki University, Institute for Quantum Beam Science, Ibaraki University

  • John Singleton

    National High Magnetic Field Lab, Los Alamos, Los Alamos National Laboratory, NHMFL, Los Alamos National Laboratory, National High Magnetic Field Laboratory, Los Alamos National Laboratory, NHMFL, Los Alamos National Lab, Los Alamos National Lab.

  • Nityan Nair

    University of California, Berkeley, Department of Physics, University of California, Berkeley, physics, University of California, Berkeley

  • Nikola Maksimovic

    Department of Physics, University of California, Berkeley, University of California, Berkeley

  • James Analytis

    University of California, Berkeley, Department of Physics, University of California, Berkeley, Physics, University of California Berkeley, Physics, University of California Berkerley, Physics, University of California, Berkeley, physics, University of California, Berkeley

  • Yuji Matsuda

    Department of Physics, Kyoto University, Department of Physics, Kyoto Univ, Dept. Phys., Kyoto Univ., Kyoto Univ, Physics, Kyoto University, Kyoto University