Dirac fermions and flat bands in the ideal kagome metal FeSn
Author(s)
Kang, Mingu; Ye, Linda; Fang, Shiang; You, Jhih-Shih; Levitan, Abraham; Han, Minyong; Facio, Jorge I; Jozwiak, Chris; Bostwick, Aaron; Rotenberg, Eli; Chan, Mun K; McDonald, Ross D; Graf, David; Kaznatcheev, Konstantine; Vescovo, Elio; Bell, David C; Kaxiras, Efthimios; van den Brink, Jeroen; Richter, Manuel; Prasad Ghimire, Madhav; Checkelsky, Joseph; Comin, Riccardo; ... Show more Show less
DownloadSubmitted version (3.135Mb)
Publisher Policy
Publisher Policy
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.
Terms of use
Metadata
Show full item recordAbstract
A kagome lattice of 3d transition metal ions is a versatile platform for correlated topological phases hosting symmetry-protected electronic excitations and magnetic ground states. However, the paradigmatic states of the idealized two-dimensional kagome lattice—Dirac fermions and flat bands—have not been simultaneously observed. Here, we use angle-resolved photoemission spectroscopy and de Haas–van Alphen quantum oscillations to reveal coexisting surface and bulk Dirac fermions as well as flat bands in the antiferromagnetic kagome metal FeSn, which has spatially decoupled kagome planes. Our band structure calculations and matrix element simulations demonstrate that the bulk Dirac bands arise from in-plane localized Fe-3d orbitals, and evidence that the coexisting Dirac surface state realizes a rare example of fully spin-polarized two-dimensional Dirac fermions due to spin-layer locking in FeSn. The prospect to harness these prototypical excitations in a kagome lattice is a frontier of great promise at the confluence of topology, magnetism and strongly correlated physics.
Date issued
2019-12Department
Massachusetts Institute of Technology. Department of PhysicsJournal
Nature Materials
Publisher
Springer Science and Business Media LLC
Citation
Kang, Mingu et al. "Dirac fermions and flat bands in the ideal kagome metal FeSn." Nature Materials 19, 2 (February 2020): 163–169 © 2019 The Author(s)
Version: Original manuscript
ISSN
1476-1122
1476-4660