Theoretical analyses of superconductivity in iron based superconductor Ba1−xKxFe2As2

This paper focuses on the theoretical analysis of superconductivity in iron based superconductor Ba1−xKxFe2As2. After reviewing the current findings on this system, we suggest that phononexciton combined mechanism gives a right order of superconducting transition temperature (TC) for Ba1−xKxFe2As2 . By developing a model Hamiltonian for the system under consideration, using double time temperature dependent Green’s function formalism and a suitable decoupling approximation technique, we have analyzed theoretically the superconductivity of iron-based superconductor Ba1−xKxFe2As2. Furthermore, by using the experimental and plausible theoretical values of the parameters in the obtained expressions, phase diagrams of superconducting transition temperature (TC) versus electron coupling constant (λe) and superconducting transition temperature (TC) versus superconducting gap parameter (Δhave been plotted. Our findings demonstrate that, as the electron coupling constant (λe) increases the superconducting transition temperature (TC) increases and vice versa and also as the temperature increases the superconducting order parameter decreases and vanishes at the transition temperature (TC) for Ba1−xKxFe2As2. Our findings are in a broad agreement with the experimental observations.Keywords: Iron based Superconductors, Green’s Function formalism, Superconducting order parameter, Ba1−xKxFe2As2.