2011/04/10 by Andriy H. Nevidomskyy, Nevidomskyy, Andriy H.
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Rare-earth and actinide compounds #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.1104.1747
4 pages, 1 figure
arxiv created 2011/04/10 · openalex publication_date 2011/04/10 · arxiv updated 2011/04/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A number of recent experiments exhibit electronic anisotropy in the iron pnictides, and there is a growing body of experimental evidence that its origin is related to orbital ordering in Fe dxz and dyz orbitals. We examine this problem in the parent compounds of the iron pnictides by a combination of ab initio band theory calculations, phenomenological Ginzburg-Landau theory of coupled orbital and magnetic order parameters, and a microscopic mean-field study of the Kugel-Khomskii model. We find that orbital ordering is sufficient to explain a number of key experimental observations, in particular a linear correlation between the orthorhombic lattice distortion and the magnetic ordered moment. We predict that orbital polarization should scale as a square of magnetic moment close to TN. Mediated by orbital polarization, the effective spin-spin exchange interactions develop anisotropy in the ab-plane, in accord with recent neutron scattering measurements.