Quasi Van der Waals Epitaxiay of Magnetic Topological Insulator on GaAs (111) Substrate

ORAL

Abstract

Magnetic topological insulator could achieve quantum anomalous Hall (QAH) effect and spin-orbit torque (SOT) switching in the same structure. This is promising for its future applications in memory or switching applications with its robust surface properties by topological protection. In this work we have grown Cr:(BixSb1-x)2Te3 and MnBi2Te4 on GaAs

(111) substrate through modulation doping by MBE (Molecular Beam Epitaxy). The doping level and the thickness of each layer is examined to tune the bandgap and the Fermi level of the whole sample. In this way, we can tune the Fermi level into the bandgap and optimize the total resistivity to achieve quantization.

Considering the van der Waals nature of the epitaxial layers, it has very weak van der Waals bonding with the substrate. This gives rise to a quasi Van der Waals epitaxial growth mode at the interface of GaAs (111) and upper epitaxial layers, where strain relaxes quickly within the 1st epitaxial layer. Growth mechanism and the influence on its transport properties are also discussed.

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Presenters

  • Yuxing Ren

    • University of California, Los Angeles

Authors

  • Yuxing Ren

    • University of California, Los Angeles

  • Lixuan Tai

    • University of California, Los Angeles

  • Hung-Yu Y Yang

    • Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
    • University of California, Los Angeles
    • Boston College

  • Xiang Dong

    • University of California, Los Angeles

  • Ting-Hsun Yang

    • University of California, Los Angeles

  • Yaochen Li

    • University of California, Los Angeles

  • Kang Wang

    • University of California, Los Angeles