2013, Rettig, L., Cortés, R., Jeevan, H.S., Gegenwart, P., Wolf, T., Fink, J., Bovensiepen, U.

Based on the results from femtosecond time-resolved photoemission, we compare three different methods for the determination of the electron–phonon coupling constant λ in Eu- and Ba-based 122 FeAs compounds. We find good agreement between all three methods, which reveal a small λ < 0.2. This makes simple electron–phonon-mediated superconductivity unlikely in these compounds.