2011/04/18 by Z. P. Yin, K. Haule, G. Kotliar
Physics and Astronomy · #cond-mat.str-el #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.1038/nmat3120
published as Nature Materials 10, 932-935 (2011) · 5 pages, 3 figures with a 5-page supplementary material
arxiv created 2011/04/18 · arxiv updated 2015/03/18
The iron pnictide and chalcogenide compounds are a subject of intensive investigations due to their high temperature superconductivity.\citea-LaFeAsO They all share the same structure, but there is significant variation in their physical properties, such as magnetic ordered moments, effective masses, superconducting gaps and Tc. Many theoretical techniques have been applied to individual compounds but no consistent description of the trends is available \citenp-review. We carry out a comparative theoretical study of a large number of iron-based compounds in both their magnetic and paramagnetic states. We show that the nature of both states is well described by our method and the trends in all the calculated physical properties such as the ordered moments, effective masses and Fermi surfaces are in good agreement with experiments across the compounds. The variation of these properties can be traced to variations in the key structural parameters, rather than changes in the screening of the Coulomb interactions. Our results provide a natural explanation of the strongly Fermi surface dependent superconducting gaps observed in experiments\citeDing. We propose a specific optimization of the crystal structure to look for higher Tc superconductors.