The low spin moment in LaOFeAs is due to a hidden multipole order caused by spin orbital ordering

2009/11/06 by Francesco Cricchio, Oscar Grånäs, Cricchio, Francesco +5
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con

paper · pdf · doi:10.48550/arxiv.0911.1342

4 pages with 4 figures

arxiv created 2009/11/06 · openalex publication_date 2009/11/06 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

An antiferro-magnetic (AF) low moment solution, 0.4 μ_B/Fe, is found in the case of LaOFeAs for an intermediately strong Coulomb interaction U of 2.5--3.0 eV. This solution is stabilized over a large moment solution due to the gain in exchange energy in the formation of large multipoles of the spin magnetization density. The multipoles are of rank four and can be understand as a kind of spin-orbital ordering. Parallels can be drawn to the stabilization of the AF order in e.g. CaCuO₂.

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