Quantum-Hall to insulator transition in ultraclean topological insulator films

ORAL

Abstract

Under a magnetic field, many two dimensional electronic systems including semiconductor 2DEGs, graphene, and topological insulators (TIs) exhibit quantum Hall effect (QHE), where Rxy is quantized at h/(νe2) while Rxx→0. In the high field limit, the QH state gives way to an insulating state in semiconductor 2DEGs as the Fermi level falls into localized states at the tail of the lowest Landau level. However, for a Dirac system such as TIs, the presence of the zeroth Landau level makes it questionable whether such a QH-to-insulator-transition (QIT) should occur at all. Here, in newly-developed ultraclean TI films, we report the first observation of QIT in TIs, with a well-defined scaling behavior. Surprisingly, the scaling analysis revealed the first example of an unconventional QIT behavior distinct from those in 2DEGs. This observation raises new questions on the origin of the insulating phase near the center of the zeroth Landau level in TIs and other Dirac materials as well.

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Presenters

  • Maryam Salehi

    Rutgers, the State University of New Jersey, Materials Science and Engineering, Rutgers, The State University of New Jersey, Materials Sci. & Eng., Rutgers University, Rutgers University, New Brunswick, Rutgers University, Rutgers University - New Brunswick

Authors

  • Maryam Salehi

    Rutgers, the State University of New Jersey, Materials Science and Engineering, Rutgers, The State University of New Jersey, Materials Sci. & Eng., Rutgers University, Rutgers University, New Brunswick, Rutgers University, Rutgers University - New Brunswick

  • Hassan Shapourian

    Physics, University of Chicago, University of Chicago

  • Ilan Rosen

    Applied Physics, Stanford University, Stanford University

  • Myung-Geun Han

    Condensed Matter Physics and Materials Science, Brookhaven National Lab, Brookhaven National Laboratory, Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, 2Condensed Matter Physics and Materials Science Departement, Brookhaven National Laboratory

  • Jisoo Moon

    Materials Sci. & Eng., Rutgers University

  • Pavel P Shibayev

    Physics, Rutgers University, Rutgers University, Rutgers University, New Brunswick

  • Deepti Jain

    Rutgers, the State University of New Jersey, Physics, Rutgers University, Rutgers University, New Brunswick, Rutgers University

  • David Goldhaber-Gordon

    Stanford University, Department of Physics, Stanford University, Stanford University, USA, Physics, Stanford University

  • Seongshik Oh

    Rutgers, the State University of New Jersey, Center for Quantum Materials Synthesis and Department of Physics and Astronomy, Rutgers, the State University of New Jersey, Physics and Astronomy, Rutgers, The State University of New Jersey, Physics, Rutgers University, Physics, Rutgers, The State University of New Jersey, Rutgers University, Rutgers University - New Brunswick