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Flat band driven itinerant magnetism in the Co-pnictides CaCo2As2 and LaCo2P2

Subires, D. ; García-Díez, M. ; Kar, A. ; Lim, C. Y. ; Li, Victoria M. ; Yannello, V. ; Carbone, Dina LU ; Gargiani, P. ; Yilmaz, T. and Dai, J. , et al. (2025) In Physical Review B 112(16).
Abstract

Flat bands can induce strong electron correlation effects that help stabilize both magnetic and superconducting states. Here, we carry out angle-resolved photoemission spectroscopy and density functional theory calculations to study the electronic structure of the Co-pnictides CaCo2As2 and LaCo2P2. We find that the kz Fermi topology of ferromagnetic LaCo2P2 is markedly two-dimensional, while the antiferromagnetic CaCo2As2 develops a 3D Fermi surface described by a zigzaglike band dispersion perpendicular to the Co-As plane. Furthermore, the magnetism is driven by the electronic correlations of the flat bands with dxy and dz2... (More)

Flat bands can induce strong electron correlation effects that help stabilize both magnetic and superconducting states. Here, we carry out angle-resolved photoemission spectroscopy and density functional theory calculations to study the electronic structure of the Co-pnictides CaCo2As2 and LaCo2P2. We find that the kz Fermi topology of ferromagnetic LaCo2P2 is markedly two-dimensional, while the antiferromagnetic CaCo2As2 develops a 3D Fermi surface described by a zigzaglike band dispersion perpendicular to the Co-As plane. Furthermore, the magnetism is driven by the electronic correlations of the flat bands with dxy and dz2 orbital character at the Fermi level. Our results link the electronic dimensionality and the magnetic order and emphasize the critical role of the As-As and P-P bond strength along the c direction to understand the electronic band structure and the rich phase diagram of transition metal pnictides.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B
volume
112
issue
16
publisher
American Physical Society
external identifiers
  • scopus:105021321604
ISSN
2469-9950
DOI
10.1103/w9rw-rjdh
language
English
LU publication?
yes
id
3dbffda3-e912-4de6-afd6-73c4297b876e
date added to LUP
2025-12-16 09:35:41
date last changed
2025-12-16 09:36:31
@article{3dbffda3-e912-4de6-afd6-73c4297b876e,
  abstract     = {{<p>Flat bands can induce strong electron correlation effects that help stabilize both magnetic and superconducting states. Here, we carry out angle-resolved photoemission spectroscopy and density functional theory calculations to study the electronic structure of the Co-pnictides CaCo<sub>2</sub>As<sub>2</sub> and LaCo<sub>2</sub>P<sub>2</sub>. We find that the kz Fermi topology of ferromagnetic LaCo<sub>2</sub>P<sub>2</sub> is markedly two-dimensional, while the antiferromagnetic CaCo<sub>2</sub>As<sub>2</sub> develops a 3D Fermi surface described by a zigzaglike band dispersion perpendicular to the Co-As plane. Furthermore, the magnetism is driven by the electronic correlations of the flat bands with d<sub>xy</sub> and d<sub>z</sub>2 orbital character at the Fermi level. Our results link the electronic dimensionality and the magnetic order and emphasize the critical role of the As-As and P-P bond strength along the c direction to understand the electronic band structure and the rich phase diagram of transition metal pnictides.</p>}},
  author       = {{Subires, D. and García-Díez, M. and Kar, A. and Lim, C. Y. and Li, Victoria M. and Yannello, V. and Carbone, Dina and Gargiani, P. and Yilmaz, T. and Dai, J. and Tallarida, M. and Vescovo, E. and Shatruk, M. and Vergniory, Maia G. and Blanco-Canosa, S.}},
  issn         = {{2469-9950}},
  language     = {{eng}},
  number       = {{16}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review B}},
  title        = {{Flat band driven itinerant magnetism in the Co-pnictides CaCo<sub>2</sub>As<sub>2</sub> and LaCo<sub>2</sub>P<sub>2</sub>}},
  url          = {{http://dx.doi.org/10.1103/w9rw-rjdh}},
  doi          = {{10.1103/w9rw-rjdh}},
  volume       = {{112}},
  year         = {{2025}},
}