2001/07/31 by Alexey B. Kuzmenko, A. B. Kuz'menko, F. P. Mena +14 · 1 citation
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Superconductivity in MgB2 and Alloys #cond-mat.supr-con
paper · pdf · doi:10.1016/s0038-1098(02)00004-2
published as Solid State Communications 121, 479-484 (2002) · RevTeX, 4 pages, 5 figures
arxiv created 2001/12/20 · openalex publication_date 2002/03/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The optical conductivity of MgB2 has been determined on a dense polycrystalline sample in the spectral range 6 meV - 4.6 eV using a combination of ellipsometric and normal incidence reflectivity measurements. σ1(ω) features a narrow Drude peak with anomalously small plasma frequency (1.4 eV) and a very broad "dome" structure, which comprises the bulk of the low-energy spectral weight. This fact can be reconciled with the results of band structure calculations by assuming that charge carriers from the 2D σ-bands and the 3D π-bands have principally different impurity scattering rates and negligible interband scattering. This also explains a surprisingly small correlation between the defect concentration and Tc, expected for a two-gap superconductor. The large 3D carrier scattering rate suggests their proximity to the localization limit.