Chemically-induced large-gap quantum anomalous Hall insulator states in III-Bi honeycombs

Authors

  • Christian P. Crisostomo Department of Physics, National Sun Yat-Sen University
  • Zhi-Quan Huang Department of Physics, National Sun Yat-Sen University
  • Chia-Hsiu Hsu Department of Physics, National Sun Yat-Sen University
  • Feng-Chuan Chuang Department of Physics, National Sun Yat-Sen University
  • Hsin Lin Graphene Research Centre and Department of Physics, National University of Singapore
  • Arun Bansil Department of Physics, Northeastern University

Abstract

The search for new novel materials has increased due to their interesting properties and promising applications. Quantum anomalous Hall (QAH) effect was recently realized in magnetic topological insulators (TIs) but only observable at extremely low temperatures. In this work, we predict large-gap QAH insulating phases in chemically functionalized III-Bi honeycombs using first-principles electronic structure calculations. QAH insulator phases were found in functionalized AlBi and TlBi, while QAH semimetals were identified in GaBi and InBi using electronic band calculation with exchange field and spin-orbit coupling. We further confirm QAH phase in these compounds by evaluating the Chern number (C) using maximally-localized Wannier functions. Most importantly, TlBi exhibits a robust with large-gap QAH insulator phases with band gap as large as 466 meV for one-sidedly functionalized and buckled honeycomb. Furthermore, the electronic band spectrum of functionalized TlBi nanoribbon with zigzag edge is shown to possess only one spin chiral edge band crossing the Fermi level within the band gap. With the recent progress of III-V materials, our results suggest that III-Bi honeycomb would provide a new platform for developing novel spintronics devices based on the QAH phase.

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Article ID

SPP-2016-5B-02

Section

Condensed Matter Physics and Materials Science

Published

2017-08-16

How to Cite

[1]
CP Crisostomo, Z-Q Huang, C-H Hsu, F-C Chuang, H Lin, and A Bansil, Chemically-induced large-gap quantum anomalous Hall insulator states in III-Bi honeycombs, Proceedings of the Samahang Pisika ng Pilipinas 34, SPP-2016-5B-02 (2017). URL: https://proceedings.spp-online.org/article/view/SPP-2016-5B-02.