Hybridization-induced gapped and gapless states on the surface of magnetic topological insulators
Xiao‐Ming Ma, Zhongjia Chen, Eike F. Schwier, Yang Zhang, Yu‐Jie Hao, Shiv Kumar, Ruie Lu, Jifeng Shao, Yuanjun Jin, Meng Zeng, Xiang-Rui Liu, Zhanyang Hao, Ke Zhang, Wumiti Mansuer, Chunyao Song, Yuan Wang, Boyan Zhao, Cai Liu, Ke Deng, Jia‐Wei Mei, K. Shimada, Yüe Zhao, Xingjiang Zhou, Bing Shen, Wen Huang, Chang Liu, Hu Xu, Kai Chen
Abstract
The Mn-Bi-Te family of materials hold promise for realizing the quantum anomalous Hall effect, provided that the topological surface states are gapped by magnetic order. However, previous ARPES measurements have revealed gapless surface Dirac cones for all Mn-Bi-Te antiferromagnetic members. Here, combining ARPES, DFT and tight-binding simulations, the authors find out that the gapless surface Dirac cones result from hybridization between surface and bulk states. This hybridization gives the surface states bulk distribution, with much reduced effective magnetic moment, and thus not sensitive to antiferromagnetic order.