Topology on a new facet of bismuth
Name
13255.full.pdf
Description
Published version
Size
1.36 MB
Format
Adobe PDF
Checksum (MD5)
c6b050e54c3374c58c5d2237d00e5727
Author(s)
Ma, Qiong
Xu, Su-Yang
Fu, Liang
Date Issued
June 13, 2019
Journal
Proceedings of the National Academy of Sciences of the United States of America
Publisher
Proceedings of the National Academy of Sciences
Citation
Hsu, Chuang-Han et al. "Topology on a new facet of bismuth." Proceedings of the National Academy of Sciences of the United States of America 116 (2019): 13255-13259 © 2019 The Author(s)
Version
Final published version
Abstract
Bismuth-based materials have been instrumental in the development of topological physics, even though bulk bismuth itself has been long thought to be topologically trivial. A recent study has, however, shown that bismuth is in fact a higher-order topological insulator featuring one-dimensional (1D) topological hinge states protected by threefold rotational and inversion symmetries. In this paper, we uncover another hidden facet of the band topology of bismuth by showing that bismuth is also a first-order topological crystalline insulator protected by a twofold rotational symmetry. As a result, its (110) ¯ surface exhibits a pair of gapless Dirac surface states. Remarkably, these surface Dirac cones are “unpinned” in the sense that they are not restricted to locate at specific k points in the (110) ¯ surface Brillouin zone. These unpinned 2D Dirac surface states could be probed directly via various spectroscopic techniques. Our analysis also reveals the presence of a distinct, previously uncharacterized set of 1D topological hinge states protected by the twofold rotational symmetry. Our study thus provides a comprehensive understanding of the topological band structure of bismuth.
Subjects
Multidisciplinary
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1073/pnas.1900527116
