ARPES study of Y 2 O 2 Bi single crystals: Intrinsic electronic structure of Bi square nets

作者：Yunbo Wu, Tongrui Li, Zhi-Peng Cao, Zhanfeng Liu, Yuliang Li, Zhiyu Shang, Xin Zheng, Hui Tian, Zongyi Wang, Yuehong Bi, Haoyang Zhou, Yi Liu, Guobin Zhang, Zhengtai Liu, Dawei Shen, Lidong Zhang, Shengtao Cui, Zhe Sun · 发表于：Chinese Physics B · 年份：2025 · DOI：10.1088/1674-1056/ae04d9 · 研究领域：Topological Materials and Phenomena、Physics of Superconductivity and Magnetism、Iron-based superconductors research

Abstract The Bi square net, a structural motif in a diverse array of layered compounds, has emerged as a desirable system for investigating the interplay between strong spin–orbit coupling, reduced dimensionality, and magnetism. We present a comprehensive study of Y 2 O 2 Bi single crystals using high-resolution angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations to elucidate the intrinsic electronic structure of the Bi square net. Our findings reveal a pronounced two-dimensional character of the electronic states, with the Bi square net dominating the low-energy electronic structure. While Y 2 O 2 Bi itself exhibits no topological features, DFT calculations on related Bi square net compounds reveal that the surrounding crystal environment can induce non-trivial topology, as exemplified by the topological insulator LiBi. This comparative study establishes a crucial benchmark for understanding Bi square net physics and informs the design of future Bi square net-based quantum materials.