2009/09/30 by Lara Benfatto, L. Benfatto, E. Cappelluti +1 · 1 citation
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Rare-earth and actinide compounds #Superconductivity in MgB2 and Alloys #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.80.214522
published as Phys. Rev. B 80, 214522 (2009) · 12 pages, 6 figures, final version
openalex publication_date 2009/12/18 · arxiv created 2010/01/11 · arxiv updated 2010/01/13 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
In this paper we provide a comprehensive analysis of different properties of pnictides both in the normal and superconducting state, with a particular focus on the optimally doped Ba_1\ensuremath-xKxFe2As2 system. We show that, by using the band dispersions experimentally measured by angle-resolved photoemission spectroscopy, a four-band Eliashberg model in the intermediate-coupling regime can account for both the measured hierarchy of the gaps and for several spectroscopic and thermodynamic signatures of low-energy renormalization. These include the kinks in the band dispersion and the effective masses determined via specific-heat and superfluid-density measurements. We also show that, although an intermediate-coupling Eliashberg approach is needed to account for the magnitude of the gaps, the temperature behavior of the thermodynamic quantities does not show in this regime a significant deviation with respect to weak-coupling BCS calculations. This can explain the apparent success of two-band BCS fits of experimental data reported often in the literature.