Evidence of a full gap in LaFeAsO₁₋ₓFₓ thin films from infrared spectroscopy

الأصل · EN

We report conventional and time-resolved infrared spectroscopy on LaFeAsO₁₋ₓFₓ superconducting thin films. The far-infrared transmission can be quantitatively explained by a two-component model including a conventional s-wave superconducting term and a Drude term, suggesting at least one carrier system has a full superconducting gap. Photo-induced studies of excess quasiparticle dynamics reveal a nanosecond effective recombination time and temperature dependence that agree with a recombination bottleneck in the presence of a full gap. The two experiments provide consistent evidence of a full, nodeless though not necessarily isotropic, gap for at least one carrier system in LaFeAsO₁₋ₓFₓ.