Dirac-Surface-State-Modulated Bilinear Magnetoresistance in Topological Insulators

ORAL

Abstract

Topological insulators (TIs) are a class of quantum materials in which the interior is insulating but electrons can travel through the two-dimensional (2D) conducting surfaces known as Dirac surface states. The Dirac surface states harbor a helical spin texture and thus provide a good platform for potential spintronic applications. Prior experiments have shown that the helical spin texture of the Dirac surface states can be resolved using bilinear magnetoresistance (BMR) measurements. The observation of BMR in previous studies was attributed to the presence of the hexagonally warped Fermi surface at the Dirac surface state in samples with heavy doping. Here, we fabricated a series of (Bi1-xSbx)2Te3 samples with different x and systematically studied their BMR. When the chemical potential is near the Dirac point and the warping effect of the Dirac surface state disappears, the BMR reaches a maximum rather than vanishes. This observation is further confirmed in a dual-gate-tuned device. Our work indicates that BMR has more complex origins than the warping effect of the Dirac surface state alone.

*This work is supported by DOE (# DE-SC0019064), the Alfred P. Sloan Research Fellowship, and NSF 2DCC-MIP (DMR-1539916).

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Presenters

  • Fei Wang

    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Department of Physics, Pennsylvania State University

Authors

  • Fei Wang

    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • ling zhang

    • Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • Ziqiao Wang

    • Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • Yifan Zhao

    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • Run Xiao

    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Physics, Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • Guang Wang

    • Pennsylvania State University
    • Department of Physics, National University of Defense Technology
    • Department of Physics, Pennsylvania State University

  • Hemian Yi

    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • lingjie zhou

    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • Ruoxi Zhang

    • Department of Physics, Pennsylvania State University

  • baitao zhang

    • Department of Physics, Pennsylvania State University
    • Pennsylvania State University

  • Moses Hung-Wai Chan

    • Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • Nitin Samarth

    • Penn Sate University
    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • Qi Li

    • Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • Weiwei Zhao

    • School of Materials Science and Engineering, Harbin Institute of Technology

  • Cui-Zu Chang

    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Department of Physics, Pennsylvania State University