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.
*This work is supported by Overseas Challenge Program for Young Researchers, Grants-in-Aids for Science Research (KAKENHI) (Nos. 18J22138, 18H01177, 18H05227) and Innovative Areas "Topological Material Science" (No. 15H05852) from JSPS.
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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
