Persistent surface states with diminishing gap in MnBi2Te4/Bi2Te3 superlattice antiferromagnetic topological insulator

DOI: 10.1016/j.scib.2020.07.032

Authors: Lixuan Xu (Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences; ShanghaiTech University and CAS-Shanghai Science Research Center; ShanghaiTech Laboratory for Topological Physics; University of Chinese Academy of Sciences) , Yuanhao Mao (National University of Defense Technology, China) , Hongyuan Wang (ShanghaiTech University and CAS-Shanghai Science Research Center; University of Chinese Academy of Sciences) , Jiaheng Li (Tsinghua University) , Yujie Chen (Tsinghua University) , Yunyouyou Xia (ShanghaiTech University and CAS-Shanghai Science Research Center; University of Chinese Academy of Sciences) , Yiwei Li (University of Oxford) , Ding Pei (University of Oxford) , Jing Zhang (ShanghaiTech University and CAS-Shanghai Science Research Center) , Huijun Zheng (ShanghaiTech University and CAS-Shanghai Science Research Center) , Kui Huang (ShanghaiTech University and CAS-Shanghai Science Research Center) , Chaofan Zhang (National University of Defense Technology, China) , Shengtao Cui (ShanghaiTech University and CAS-Shanghai Science Research Center) , Aiji Liang (ShanghaiTech University and CAS-Shanghai Science Research Center; Advanced Light Source) , Wei Xia (ShanghaiTech University and CAS-Shanghai Science Research Center; ShanghaiTech Laboratory for Topological Physics; University of Chinese Academy of Sciences) , Hao Su (ShanghaiTech University and CAS-Shanghai Science Research Center) , Sungwon Jung (Diamond Light Source) , Cephise Cacho (Diamond Light Source) , Meixiao Wang (ShanghaiTech University and CAS-Shanghai Science Research Center) , Gang Li (ShanghaiTech University and CAS-Shanghai Science Research Center; ShanghaiTech Laboratory for Topological Physics) , Yong Xu (Tsinghua University; Frontier Science Center for Quantum Information; RIKEN Center for Emergent Matter Science (CEMS)) , Yanfeng Guo (ShanghaiTech University and CAS-Shanghai Science Research Center) , Lexian Yang (Tsinghua University; Frontier Science Center for Quantum Information) , Zhongkai Liu (ShanghaiTech University and CAS-Shanghai Science Research Center; ShanghaiTech Laboratory for Topological Physic) , Yulin Chen (ShanghaiTech University and CAS-Shanghai Science Research Center; ShanghaiTech Laboratory for Topological Physics; singhua University; University of Oxford) , Mianheng Jiang (Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences; ShanghaiTech University and CAS-Shanghai Science Research Center; University of Chinese Academy of Sciences)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Science Bulletin

State: Published (Approved)
Published: July 2020
Diamond Proposal Number(s): 23648 , 24827

Abstract: Magnetic topological quantum materials (TQMs) provide a fertile ground for the emergence of fascinating topological magneto-electric effects. Recently, the discovery of intrinsic antiferromagnetic (AFM) topological insulator MnBi2Te4 that could realize quantized anomalous Hall effect and axion insulator phase ignited intensive study on this family of TQM compounds. Here, we investigated the AFM compound MnBi4Te7 where Bi2Te3 and MnBi2Te4 layers alternate to form a superlattice. Using spatial- and angle-resolved photoemission spectroscopy, we identified ubiquitous (albeit termination dependent) topological electronic structures from both Bi2Te3 and MnBi2Te4 terminations. Unexpectedly, while the bulk bands show strong temperature dependence correlated with the AFM transition, the topological surface states with a diminishing gap show negligible temperature dependence across the AFM transition. Together with the results of its sister compound MnBi2Te4, we illustrate important aspects of electronic structures and the effect of magnetic ordering in this family of magnetic TQMs.

Journal Keywords: Spatially resolved angle-resolved photoemission spectroscopy; Electronic band structure; Quantum anomalous Hall effect; Magnetic topological insulator

Diamond Keywords: Antiferromagnetism

Subject Areas: Materials, Physics


Instruments: I05-ARPES

Added On: 05/08/2020 10:46

Discipline Tags:

Quantum Materials Hard condensed matter - electronic properties Physics Magnetism Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)