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Modeling non-local transport measurements of a quantum anomalous Hall insulator

ORAL

Abstract

The quantum anomalous Hall (QAH) effect, characterized by a quantized Hall resistance at zero magnetic field, has been found in magnetically-doped topological insulators topological insulators such as Cr-doped (Bi,Sb)2Te3. A resistance standard based on the QAH effect promises to change the way we disseminate electrical standards by allowing the integration of quantum resistance and voltage standards into a single cryostat. Efforts to model the transport behavior of QAH insulators, particularly as quantization breaks down, have led to two main approaches: (i) a bulk conductivity model which treats the charge transport properties with a uniform bulk conductivity model and (ii) an edge-only model which considers a combination of chiral and dissipative quasihelical edge states as the transport channels. Both models can predict various features of the transport behavior of QAH insulators - at least qualitatively. A direct comparison of these models with conventional and non-local experimental resistance measurements is made in an effort to highlight features that are not well described. We discuss how QAH models could be improved.

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Presenters

  • Valery Ortiz Jimenez

    Physical Measurement Laboratory, National Institute of Standards and Technology, National Institute of Standards and Technology (NIST)

Authors

  • Valery Ortiz Jimenez

    Physical Measurement Laboratory, National Institute of Standards and Technology, National Institute of Standards and Technology (NIST)

  • Ngoc Thanh Mai Tran

    University of Maryland College Park, University of Maryland, Joint Quantum Institute, University of Maryland

  • Linsey K Rodenbach

    Department of Physics, Stanford University

  • Molly P Anderson

    Department of Materials Science and Engineering, Stanford University

  • Peng Zhang

    UCLA, Department of Electrical and Computer Engineering, University of California

  • Lixuan Tai

    University of California, Los Angeles, Department of Electrical and Computer Engineering, University of California

  • Kang-Lung L Wang

    University of California, Los Angeles, Department of Electrical and Computing Engineering, University of California

  • David Goldhaber-Gordon

    Stanford Institute for Materials & Energy Sciences, Stanford University, Stanford University, Department of Physics, Stanford University

  • Albert F Rigosi

    National Institute of Standards and Technology, Physical Measurement Laboratory, National Institute of Standards and Technology, National Institute of Standards and Technology (NIST)

  • Paul Haney

    National Institute of Standards and Technology (NIST), Physical Measurement Laboratory, National Institute of Standards and Technology

  • Curt A Richter

    National Institute of Standards and Technology (NIST), Physical Measurement Laboratory, National Institute of Standards and Technology