2008/07/07 by Gang Li, G. Li, W. Z. Hu +9 · 4 citations
Materials Science · Physics and Astronomy · #Condensed matter physics #Energy (signal processing) #Infrared #Infrared spectroscopy #Iron-based superconductors research #Materials science #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Spectroscopy #Superconductivity #Superconductivity in MgB2 and Alloys #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.101.107004
published as Phys. Rev. Lett. 101, 107004 (2008) · 4 pages, 5 figures
arxiv created 2008/07/07 · openalex publication_date 2008/09/05 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We performed optical spectroscopy measurement on a superconducting Ba0.6K0.4Fe2As2 single crystal with Tc=37 K. Formation of the superconducting energy gaps in the far-infrared reflectance spectra below Tc is clearly observed. A flat and close to unity reflectance is observed roughly below 150 cm^\ensuremath-1 for T\ensuremath≪Tc, following an s-wave pairing line shape. A more rapid decrease occurs near 200 cm^\ensuremath-1, leading to a peak in the ratio of the reflectance at T\ensuremath≪Tc over that for T\ensuremath≥Tc. We determined the absolute value of the penetration depth at 10 K as \ensuremathλ\ensuremath≃2000\ifmmode±\else\textpm\fi80 \AA. A spectral weight analysis shows that the Ferrell-Glover-Tinkham sum rule is satisfied at low energy scale, less than 6\ensuremathΔ.