Correlation effects obtained from optical spectra of Fe-pnictides using an extended Drude-Lorentz model analysis

We introduce an analysis model, extended Drude–Lorentz and apply it to Fe-pnictide systems extract their electron–boson spectral density functions (or correlation spectra). The model consists of Drude mode for describing correlated charge carriers Lorentz modes interband transitions. can be obtained by a reverse process starting from the function extending optical self-energy and, eventually, conductivity. Using we K-doped BaFe2As2 (Ba-122) at four different doping levels. discuss doping-dependent properties Ba-122. also include pseudogap effects in using this approach. Therefore, approach is very helpful understanding analyzing measured spectra strongly electron systems, including high-temperature superconductors (cuprates Fe-pnictides).