First-principles calculation of structural and electronic properties of MnBi_2-xSb_xTe₄

Chen-Chia Hsu^1*, Yu-Chang Chen², Ken-Ming Lin², Cheng-Chien Chen³, Jiunn-Yuan Lin¹

¹Institute of Physics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
²Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
³Department of Physics, University of Alabama at Birmingham, Birmingham, Alabama, USA

* Presenter:Chen-Chia Hsu, email:tonyhsu.sc10@nycu.edu.tw

MnBi₂Te₄ is an antiferromagnetic topological insulator, where topological phase transition can be induced by magnetic field. Sb substitution of Bi also can affect the material property, by effectively tuning the carriers from electrons to holes. In this study, we simulate Sb-doped MnBi_2-xSb_xTe₄ using the virtual crystal approximation (VCA) and special quasi-random structure (SQS) methods. We also employ density functional theory plus U (DFT+U) method with spin-orbit interaction to calculate the electronic structures of MnBi_2−xSb_xTe₄ in different magnetic phases and various Sb concentrations. Our results can help understand how Sb substitution and magnetism influence the structural, electronic, and topological properties of the material.
We are grateful to NSTC of Taiwan and AFOSR of US for supporting this project (NSTC-110-2124-M-A49-007-MY3).

Keywords: Topological insulator, Lattice parameter, Electronic structure, First-principles calculation