Published January 15, 2022 | Version v1
Journal Article Open

Ferromagnetic helical nodal line and Kane-Mele spin-orbit coupling in kagome metal Fe₃Sn₂

Abstract

The two-dimensional kagome lattice hosts Dirac fermions at its Brillouin zone corners K and K′, analogous to the honeycomb lattice. In the density functional theory electronic structure of ferromagnetic kagome metal Fe₃Sn₂, without spin-orbit coupling, we identify two energetically split helical nodal lines winding along z in the vicinity of K and K′ resulting from the trigonal stacking of the kagome layers. We find that hopping across A-A stacking introduces a layer splitting in energy while that across A-B stacking controls the momentum space amplitude of the helical nodal lines. We identify the latter to be one order of magnitude weaker than the former owing to the underlying d-orbital degrees of freedom. The effect of spin-orbit coupling is found to resemble that of a Kane-Mele term, where the nodal lines can either be fully gapped to quasi-two-dimensional massive Dirac fermions, or remain gapless at discrete Weyl points depending on the ferromagnetic moment orientation. Aside from numerically establishing Fe₃Sn₂ as a model Dirac kagome metal by clarifying the roles played by interplane coupling, our results provide insights into materials design of topological phases from the lattice point of view, where paradigmatic low dimensional lattice models often find realizations in crystalline materials with three-dimensional stacking.

Copyright and License

© 2022 American Physical Society.

Acknowledgement

We are grateful to D. Vanderbilt, B. Lian, J.-S. You, and T. Kurumaji for fruitful discussions.

Funding

This work was funded, in part, by the Gordon and Betty Moore Foundation EPiQS Initiative, Grant No. GBMF9070 to J.G.C. and NSF grant DMR-1554891. L.Y., M.K., E.K., and R.C. acknowledge support by the STC Center for Integrated Quantum Materials, NSF Grant No. DMR-1231319. L.Y. acknowledges support from the Heising-Simons Foundation. S.F. is supported by a Rutgers Center for Material Theory Distinguished Postdoctoral Fellowship. M.P.G. acknowledges the equipment grant supported by Alexander von Humboldt Foundation, Germany. M.K. acknowledges support from Max Planck POSTECH Korea Research Initiative, the National Research Foundation of Korea, Ministry of Science and ICT (Grant No. 2016K1A4A4A01922028). J.v.d.B. acknowledges financial support from the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) via SFB1143 Project No. A5 and under German Excellence Strategy through the Wurzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter ct.qmat (EXC 2147, Project No. 390858490). The computations in this paper were run on the FASRC Cannon cluster supported by the FAS Division of Science Research Computing Group at Harvard University and at the computer clusters at IFW Dresden, Germany. S.F., M.P.G. and M.R. acknowledge the technical assistance from U. Nitzsche for the latter. J.L. acknowledges the support from the Hong Kong Research Grants Council (26302118, 16305019 and N_HKUST626/18).

Attached Files

Published article: PhysRevB.105.035107.pdf

Supporting Information: Fe3Sn2_SI.pdf

Files

PhysRevB.105.035107.pdf

Files (14.2 MB)

Name Size Download all
md5:2d74db643473f85a229b06fc024777e8
11.4 MB Preview Download
md5:07f37169e13ea324ee0df7b0f68f7562
2.8 MB Preview Download

Additional details

Additional titles

Alternative title
Ferromagnetic helical nodal line and Kane-Mele spin-orbit coupling in kagome metal Fe3Sn2

Identifiers

ISSN
2469-9969

Funding

Gordon and Betty Moore Foundation
GBMF9070
National Science Foundation
DMR-1554891
National Science Foundation
DMR-1231319
Heising-Simons Foundation
Rutgers, The State University of New Jersey
Alexander von Humboldt Foundation
Max Planck Society
National Research Foundation of Korea
2016K1A4A4A01922028
Deutsche Forschungsgemeinschaft
SFB1143, A5
Deutsche Forschungsgemeinschaft
EXC 2147, 390858490
Research Grants Council, University Grants Committee
26302118
Research Grants Council, University Grants Committee
16305019
Research Grants Council, University Grants Committee
N_HKUST626/18

Dates

Accepted
2021-11-24