Extended Data Fig. 4: Comparison of the optical conductivity of thin films to single crystals.
From: Planckian scattering and parallel conduction channels in an iron chalcogenide superconductor
Comparison of the real part of the optical conductivity of the x = 0.45 thin film (solid lines) in this study and a x = 0.45 single crystal (dashed) measured with FTIR by C. Homes et al, reproduced from (17, 20) At temperatures above the transition (20 and 10 K) the frequency dependence and magnitude are remarkably similar. Below the transition the single crystals appear to show a stronger gap, however these frequencies are at the limit of the FTIR spectrometer. Overall, the qualitative agreement of the spectra give us confidence that we are in the bulk limit.
