The optical conductivity of (K,Rb,Cs)Fe₂As₂

We measured the temperature dependence of the optical conductivity of XFe₂As₂ iron pnictides, where X = K, Rb, and Cs. A two-Drude analysis of the data quantitatively describes the data of all compositions. From this analysis, we extracted the scattering rate and effective mass for each Drude contribution. Both our parameters and the overall optical conductivity are compared to first principles DMFT calculations. We discuss the tempeature behavior of the scattering rate as a funciton of X. The comparison of the full optical conductivity to DMFT caculations allows us to infer the evolution of the electronic correlations strength with ionic replacement.

Collaborators: L. de' Medici, (ESPCI Paris, France), F. Hardy, A.A. Haghighirad (Karlsruhe Institute of Technology, Germany)