Realization of a tunable surface Dirac gap in Sb-doped <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>MnBi</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>
Xiao‐Ming Ma, Yufei Zhao, Ke Zhang, Shiv Kumar, Ruie Lu, Jiayu Li, Qiushi Yao, Jifeng Shao, Fuchen Hou, Xuefeng Wu, Meng Zeng, Yu‐Jie Hao, Zhanyang Hao, Yuan Wang, Xiang-Rui Liu, Huiwen Shen, Hongyi Sun, Jia‐Wei Mei, K. Miyamoto, Taichi Okuda, Masashi Arita, Eike F. Schwier, K. Shimada, Ke Deng, Cai Liu, Junhao Lin, Yüe Zhao, Kai Chen, Qihang Liu, Chang Liu
Abstract
Intrinsic magnetic topological insulators, exemplified by MnBi${}_{2}$Te${}_{4}$, receive considerable research interest, due to the potential quantum anomalous Hall state and axion insulator phase at higher temperatures. Opening up an energy gap at the topological surface state is crucial for the realization of these effects. Here, the authors utilize systematic ARPES data to show that a gapped Dirac cone can be realized in Sb-doped MnBi${}_{2}$Te${}_{4}$. This gap remains immune regardless of the magnetic phase of the bulk system, while it increases monotonically with the density of Sb dopants.