Dirac fermions and flat bands in the ideal kagome metal FeSn

Mingu Kang, Linda Ye, Shiang Fang, Jhih Shih You, Abe Levitan, Minyong Han, Jorge I. Facio, Chris Jozwiak, Aaron Bostwick, Eli Rotenberg, Mun K. Chan, Ross D. McDonald, David Graf, Konstantine Kaznatcheev, Elio Vescovo, David C. Bell, Efthimios Kaxiras, Jeroen van den Brink, Manuel Richter, Madhav Prasad GhimireJoseph G. Checkelsky*, Riccardo Comin

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

70 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)163-169
Number of pages7
JournalNature Materials
Volume19
Issue number2
DOIs
Publication statusPublished - 2020 Feb 1
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'Dirac fermions and flat bands in the ideal kagome metal FeSn'. Together they form a unique fingerprint.

Cite this