Topological insulator interfaced with ferromagnetic insulators: Bi<sub>2</sub>Te<sub>3</sub> thin films on magnetite and iron garnets

ORAL

Abstract

We have grown Bi2Te3 thin films on Y3Fe5O12(111), Tm3Fe5O12(111), Fe3O4(111), and Fe3O4(100) by molecular beam epitaxy with minimal chemical reaction at the interface. Electrical transport measurements were performed to study the magnetism induced by the proximity effect in the topological insulator in conjunction to the ferromagnetic insulators. We observed the anomalous Hall effect on these heterostructures. Magnetoresistance measurements at low temperature reveal a suppression of the weak antilocalization, indicating a possible topological surface state gap opening induced by the magnetic proximity effect. However, we did not observe any obvious x-ray magnetic circular dichroism (XMCD) on the Te M45 edges. The results suggest that the ferromagnetism induced by the magnetic proximity effect via Van der Waals bonding in Bi2Te3 by is too weak to be detected by XMCD, but still can be observed by electrical transport measurements. This is consistent with published density-functional theory results on topological insulator/magnetic insulator heterostructure showing that only a small band gap of 9 meV is induced by the magnetic proximity effect.

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Presenters

  • Chi-Nan Wu

    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

Authors

  • Chi-Nan Wu

    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

  • Vanda M Pereira

    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

  • Simone G Altendorf

    • Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

  • Sheng-Chieh Liao

    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

  • Cheng-En Liu

    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

  • Alexander Komarek

    • Max Planck Institute
    • Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

  • Mengxin Guo

    • Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
    • Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan

  • Hong-Ji Lin

    • National Synchrotron Radiation Research Center, Hsinchu, Taiwan

  • Chien-Te Chen

    • National Synchrotron Radiation Research Center, Hsinchu, Taiwan

  • Minghwei Hong

    • Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei, Taiwan
    • Natl Taiwan Univ
    • Department of Physics, National Taiwan University
    • Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 10617, Taiwan
    • Department of Physics, National Taiwan University, Taipei, Taiwan

  • Jueinai Kwo

    • Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
    • Natl Tsing Hua Univ
    • Department of Physics, National Tsing Hua University
    • Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan

  • Liu Tjeng

    • Max Planck Inst
    • Max-Planck Institute for Chemical Physics of Solids Dresden
    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
    • Max Planck Institute for Chemical Physics of Solids