Study of the structure of a superconducting state of Co-doped BaFe2As2 multiband compounds

• Published in: JETP letters 2014-11, Vol.100 (5), p.328-335
• Main Authors: Karakozov, A. E., Gorshunov, B. P., Ponomarev, Ya. G., Prokhorov, A. S., Nozdrin, V. S., Magnitskaya, M. V., Zhukova, E. S., Iida, K., Dressel, M., Zapf, S., Haindl, S.
• Format: Article
• Language: English
• Subjects: Atomic; Biological and Medical Physics; Biophysics; Condensed Matter; Molecular; Optical and Plasma Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Quantum Information Technology; Solid State Physics; Spintronics
• ISSN: 0021-3640; 1090-6487
• DOI: 10.1134/S002136401417007X

The terahertz and infrared spectra of the complex dynamic conductivity, as well as the temperature dependences of the density of a superconducting condensate and the electronic specific heat of superconducting Ba(Fe 1 − x Co x ) 2 As 2 compounds, have been analyzed within a Bardeen-Cooper-Schrieffer-like model of a multiband superconductor with strong coupling. It has been shown that the superconducting state of these compounds is determined by three (one electronic and two hole) weakly interacting condensates. The order parameters of the condensates are: Δ 1 ≈ 15 cm −1 , Δ 2 ≈ 21 cm −1 , and Δ 3 ≈ 30–35 cm −1 . The results significantly refine the existing notions on the structure of the superconducting state of Co-doped BaFe 2 As 2 multiband compounds.