Measurements of Non-Local Resistances in the Quantum Anomalous Hall Regime

ORAL

Abstract

The quantum anomalous Hall effect (QAHE) is promising for revolutionizing the dissemination of quantum electrical standards. An improved understanding of the limitations of the QAHE are needed to implement such next generation standards. We report experimental results of conventional resistance and non-local measurements in the QAH regime of a Hall bar geometry device made from a high-quality 6 quintuple layer modulation-doped sample of the magnetic topological insulator, Cr-doped (BiSb)2Te3. At dilution refrigerator temperatures (≈10 mK) this sample is well-quantized to within a few ppm of h/e2. We observe non-local resistances at temperatures above the well-quantized QAHE regime. They are measured as a function of temperature from the QAHE regime to 100 K which is well above the Curie temperature. The behavior is also characterized as a function of gate bias and current amplitude. We will discuss possible interpretations for these striking results.

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Presenters

  • Curt A Richter

    • National Institute of Standards and Tech
    • National Institute of Standards and Technology

Authors

  • Curt A Richter

    • National Institute of Standards and Tech
    • National Institute of Standards and Technology

  • Valery Ortiz Jimenez

    • Physical Measurement Laboratory, National Institute of Standards & Technology, Gaithersburg, Maryland.

  • Ngoc Thanh Mai Tran

    • National Institute of Standards and Technology
    • Physical Measurement Laboratory, National Institute of Standards & Technology, Gaithersburg, Maryland. & Joint Quantum Institute, University of Maryland, College Park, MD
    • Physical Measurement Laboratory, NIST

  • Linsey K Rodenbach

    • Stanford Univ
    • Stanford University
    • Department of Physics, Stanford University, Stanford, California

  • Molly P Andersen

    • Stanford University
    • Department of Physics, Stanford University, Stanford, California

  • Peng Zhang

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

  • Lixuan Tai

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

  • Paul Haney

    • National Institute of Standards and Technology

  • Kang L Wang

    • University of California, Los Angeles
    • Departments of Electrical and Computer Engineering, Physics and Astronomy, University of California, Los Angeles, California

  • David Goldhaber-Gordon

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

  • Albert F Rigosi

    • Physical Measurement Laboratory, National Institute of Standards & Technology
    • National Institute of Standards and Technology