Evidence for multiple superconducting gaps in optimally doped BaFe${}_{1.87}$Co${}_{0.13}$As${}_2$ from infrared spectroscopy

K. W. Kim, M. Rössle, A. Dubroka +3

We performed combined infrared reflection and ellipsometry measurements of the in-plane optical reponse of single crystals of the pnictide high temperature superconductor BaFe$_{1.…