@article{c96cf673613d44b595c0603c24188d65,
title = "Band topology of bismuth quantum films",
abstract = "Bismuth has been the key element in the discovery and development of topological insulator materials. Previous theoretical studies indicated that Bi is topologically trivial and it can transform into the topological phase by alloying with Sb. However, recent high-resolution angle-resolved photoemission spectroscopy (ARPES) measurements strongly suggested a topological band structure in pure Bi, conflicting with the theoretical results. To address this issue, we studied the band structure of Bi and Sb films by ARPES and first-principles calculations. The quantum confinement effectively enlarges the energy gap in the band structure of Bi films and enables a direct visualization of the ℤ2 topological invariant of Bi. We find that Bi quantum films in topologically trivial and nontrivial phases respond differently to surface perturbations. This way, we establish experimental criteria for detecting the band topology of Bi by spectroscopic methods.",
author = "Chang, {Tay Rong} and Qiangsheng Lu and Xiaoxiong Wang and Hsin Lin and T. Miller and Chiang, {Tai Chang} and Guang Bian",
note = "Funding Information: Funding: T.-R.C. was supported by the Young Scholar Fellowship Program from the Ministry of Science and Technology (MOST) in Taiwan, under a MOST grant for the Columbus Program MOST108-2636-M-006-002, National Cheng Kung University, Taiwan, and National Center for Theoretical Sciences, Taiwan. This work was supported partially by the MOST, Taiwan, Grant MOST107-2627-E-006-001. This research was supported in part by Higher Education Sprout Project, Ministry of Education to the Headquarters of University Advancement at National Cheng Kung University (NCKU). H.L. acknowledges Academia Sinica, Taiwan, for the support under Innovative Materials and Analysis Technology Exploration (AS-iMATE-107-11). This research is supported by the Fundamental Research Funds for the Central Universities under grant No. 30917011338 (XXW), and the US National Science Foundation under grant number NSF DMR-1809160 (GB) and NSF DMR-1305583 (TCC). Funding Information: T.-R.C. was supported by the Young Scholar Fellowship Program from the Ministry of Science and Technology (MOST) in Taiwan, under a MOST grant for the Columbus Program MOST108-2636-M-006-002, National Cheng Kung University, Taiwan, and National Center for Theoretical Sciences, Taiwan. This work was supported partially by the MOST, Taiwan, Grant MOST107-2627-E-006-001. This research was supported in part by Higher Education Sprout Project, Ministry of Education to the Headquarters of University Advancement at National Cheng Kung University (NCKU). H.L. acknowledges Academia Sinica, Taiwan, for the support under Innovative Materials and Analysis Technology Exploration (AS-iMATE-107-11). This research is supported by the Fundamental Research Funds for the Central Universities under grant No. 30917011338 (XXW), and the US National Science Foundation under grant number NSF DMR-1809160 (GB) and NSF DMR-1305583 (TCC).",
year = "2019",
month = oct,
doi = "10.3390/cryst9100510",
language = "English",
volume = "9",
journal = "Crystals",
issn = "2073-4352",
publisher = "Multidisciplinary Digital Publishing Institute (MDPI)",
number = "10",
}