Kinetic frustration and the nature of the magnetic and paramagnetic states in iron pnictides and iron chalcogenides.

By Z. Yin, K. Haule, Gabriel Kotliar. Nature Materials, 2011

677 citations recorded by the source corpus.

The iron pnictide and chalcogenide compounds are a subject of intensive investigations owing to their surprisingly high temperature superconductivity. They all share the same basic building blocks, but there is significant variation in their physical properties, such as magnetic ordered moments, effective masses, superconducting gaps and transition temperature (T(c)). Many theoretical techniques have been applied to individual compounds but no consistent description of the microscopic origin of these variations is available. Here we carry out a comparative theoretical study of a large number of iron-based compounds in both their magnetic and paramagnetic states. Taking into account correlation effects and realistic band structures, we describe well the trends in all of the physical properties such as the ordered moments, effective masses and Fermi surfaces across all families of iron compounds, and find them to be in good agreement with experiments. We trace variation in physical properties to variations in the key structural parameters, rather than changes in the screening of the Coulomb interactions. Our results also provide a natural explanation of the strongly Fermi-surface-dependent superconducting gaps observed in experiments.

Subfields: Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/14c52e00309d1868f676264339d501505bb42076

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In Electronic, Optical and Magnetic Materials

1. E. Dagotto
2. P. Dai
3. R. Fernandes
4. D. Feng
5. Xianhui Chen
6. Jiangping Hu
7. Fu-Chun Zhang
8. Tao Xiang

Citations in the corpus

• Magnetism and its microscopic origin in iron-based high-temperature superconductors (2012, methodology): “Several parent compounds of these materials, such as LaFeAsO, BaFe2As2, NaFeAs and FeTe, are not insulators but semimetals11–14.”
• Superconductivity in iron compounds (2011, background): “Since DFT calculations do not properly include electronic correlations [see Yin, Haule, and Kotliar (2011) for a comparison of DFTwith DFTþ DMFT (dynamical mean field theory) Fermi surface calculations], this difference in the determined magnetic moment implies that such correlations may be…”
• Colloquium: The unexpected properties of alkali metal iron selenide superconductors (2012, background): “…study of the influence of correlations, not only in selenides but in pnictides as well, arrives to the conclusion that the weak coupling Fermi Surface nesting picture is incomplete and the intermediate U coupling regime is more realistic (Yin, Haule, and Kotliar, 2011; Dai, Hu, and Dagotto, 2012).”
• Magnetism, Superconductivity, and Spontaneous Orbital Order in Iron-Based Superconductors: Which Comes First and Why? (2016, background): “We emphasize that these parameters already absorb regular renormalizations of the dispersions due to interactions, including the renormalizations of the bandwidths [46] and terms that shift separately chemical potentials of hole and electron bands [47].”
• Iron-based high transition temperature superconductors (2014, background): “However, there is an effective local moment [134], and the coupling between the itinerant electrons and local moments (which are the two sides of the same coin) gives the Hund’s rule coupling, themain correlation source in these compounds [179,180].”