Topological flat bands in frustrated kagome lattice CoSn
Name
s41467-020-17465-1.pdf
Description
Published version
Size
2.96 MB
Format
Adobe PDF
Checksum (MD5)
d4082844bafbe36e09bc49fba9be435d
Author(s)
Kang, Mingu
Fang, S
Ye, Linda
Po, Hoi Chun
Denlinger, J
Jozwiak, C
Bostwick, A
Rotenberg, E
Kaxiras, E
Checkelsky, Joseph
Date Issued
August 2020
Journal
Nature Communications
Publisher
Springer Science and Business Media LLC
Citation
Kang, Mingu et al. "Topological flat bands in frustrated kagome lattice CoSn." Nature Communications 11, 1 (August 2020): 4004 © 2020 The Author(s)
Version
Final published version
Abstract
Electronic flat bands in momentum space, arising from strong localization of electrons in real space, are an ideal stage to realize strongly-correlated phenomena. Theoretically, the flat bands can naturally arise in certain geometrically frustrated lattices, often with nontrivial topology if combined with spin-orbit coupling. Here, we report the observation of topological flat bands in frustrated kagome metal CoSn, using angle-resolved photoemission spectroscopy and band structure calculations. Throughout the entire Brillouin zone, the bandwidth of the flat band is suppressed by an order of magnitude compared to the Dirac bands originating from the same orbitals. The frustration-driven nature of the flat band is directly confirmed by the chiral d-orbital texture of the corresponding real-space Wannier functions. Spin-orbit coupling opens a large gap of 80 meV at the quadratic touching point between the Dirac and flat bands, endowing a nonzero Z2 invariant to the flat band. These findings demonstrate that kagome-derived flat bands are a promising platform for novel emergent phases of matter at the confluence of strong correlation and topology.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1038/s41467-020-17465-1
