Evolution of band topology with antisite defects in the Sb-doped MnBi4Te7

Shang-Wei Lien^1*, Chaowei Hu², Tay-Rong Chang^1,3,4, Ni Ni²

¹Department of Physics, National Cheng Kung University, Tianan, Taiwan
²Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, USA
³Center for Quantum Frontiers of Research & Technology, Tainan, Taiwan
⁴National Taiwan University, Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan

* Presenter:Shang-Wei Lien, email:C24016033@gmail.com

Magnetic topological materials attract worldwide attention because the interplay between band topology and magnetism may lead to novel topological quantum phenomena, such as quantum anomalous Hall effect and quantized magnetoelectric effect. Here we propose a tunable magnetic and topological state in Sb doping a newly discovered intrinsic antiferromagnetic (AFM) topological insulator (TI) MnBi4Te7 [1]. Our first-principles calculation shows that the topological ground state transfer from AFM TI to ferromagnetic axion insulator in the low doping region, and then exhibit a type-I ferrimagnetic Weyl semimetal that resulted from strong antisite disorder in the high doping region. Our calculation demonstrates that the doping series provides a fruitful platform with continuously tunable magnetism and topology for investigating emergent phenomena.

Keywords: Magnetic topological materials, quantum anomalous Hall effect, ferromagnetic axion insulator, Weyl semimetal