Two-band BCS superconductivity in Ba(Fe0.9Co0.1)2As2
cond-mat.supr-con
/ Authors
E. G. Maksimov, A. E. Karakozov, B. P. Gorshunov, V. S. Nozdrin, A. A. Voronkov, E. S. Zhukova, S. S. Zhukov, Dan Wu, M. Dressel, S. Haindl
and 2 more authors
/ Abstract
The conductivity and permittivity optical spectra of iron-pnictide Ba(Fe0.9Co0.1)2As2 film (Tc=20 K) are analyzed. In the superconducting state, at all temperatures up to Tc the temperature dependences of the magnetic field penetration depth and of the superconducting condensate density are well described within the generalized two-band BCS model with intraband and interband pairing interactions considered. It is shown that the smaller superconducting energy gap 2Δ = 3.7 meV develops in the electronic subsystem while the larger gap 2Δ >= 7 meV opens in the hole subsystem. The normal state parameters (plasma frequencies and scattering rates) of electron and hole conduction bands are determined. At all temperatures the obtained data are consistent with the results of electronic photoemission experiments on Ba(Fe1-x Cox)2As2.