2025/03/04 by David Subires, Subires, D., Mikel García‐Díez +27
Materials Science · Physics and Astronomy · #Crystal Structures and Properties #FOS: Physical sciences #Iron-based superconductors research #Materials Science (cond-mat.mtrl-sci) #Rare-earth and actinide compounds #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2503.02728
openalex publication_date 2025/03/04 · openalex created_date 2025/10/19 · openalex updated_date 2026/07/28
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, while the kz Fermi topology of ferromagnetic LaCo2P2 is markedly 2-dimensional, antiferromagnetic CaCo2As2 develops a 3D Fermi surface described by a zig-zag-like 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.