Direct observation of a nodeless superconducting energy gap in the optical conductivity of iron-pnictides

B. Gorshunov, D. Wu, A. A. Voronkov +7

The temperature-dependent optical reflectivity and complex transmissivity of an epitaxially grown Ba(Fe${}_{0.9}$Co${}_{0.1}$)${}_2$As${}_2$ thin film were measured and the optical conduct…