Magneto-transport properties of bulk-insulating topological insulators (Bi,Sb)<sub>2</sub>Te<sub>3</sub> on thulium iron garnets

ORAL

Abstract

Breaking time-reversal symmetry in topological insulators (TIs) via magnetic proximity effect attracted intense studies. The spin dynamics of magnetic insulators (MIs) interfacing with TIs has been investigated by ferromagnetic resonance,1 and the magneto-transport of magnetized Bi2Se3 by MIs has been reported,2 yet the crucial bulk-insulating TI, (Bi,Sb)2Te3 (BST) requires further thorough study. In this work properties of BST thin films deposited by molecular beam epitaxy on a-Al2O3 and tensile-strained Tm3Fe5O12 (TmIG) of perpendicular magnetic anisotropy are reported. By adopting the low-temperature growth method,3 we demonstrated a significantly improved film growth evidenced by streaky reflection high-energy electron diffraction patterns attained at the first quintuple layer of BST on TmIG. TIs were confirmed bulk-insulating by electric transport and angle-resolved photoemission spectroscopy. We observed anomalous Hall effect up to 300K accompanied by suppressed weak anti-localization. Our work promotes the realization of quantum anomalous Hall effect at higher temperature and future TI-based devices.

1. Y. T. Fanchiang et al., Nat. Commun. 9, 223 (2018).
2. S. R. Yang et al., Phys. Rev. B 100, 045138 (2019).
3. C. C. Chen, et al., Appl. Phys. Lett. 114, 031601 (2019).

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Presenters

  • Chun-Chia Chen

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

Authors

  • Chun-Chia Chen

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

  • Shang Rong Yang

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

  • Yu-Ting Fanchiang

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

  • Wei-Jhih Zou

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

  • Mengxin Guo

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

  • Chao-Kai Cheng

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

  • Sheng-Wen Huang

    • 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

  • Keng-Yung Lin

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

  • Ko-Hsuan Chen

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