2002/02/28 by Sergey V. Barabash, S. V. Barabash, D. Stroud +1 · 3 citations
Engineering · Physics and Astronomy · #Computer science #Database #Physics #Physics of Superconductivity and Magnetism #Superconducting Materials and Applications #Superconductivity in MgB2 and Alloys #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.66.172501
published in Physical review. B, Condensed matter 66(17) (American Physical Society)
arxiv created 2002/08/12 · openalex publication_date 2002/11/04 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We analyze the qualitative features in the transition spectra of a model superconductor with multiple energy gaps, using a simple extension of the Mattis-Bardeen expression for probes with case I and case II coherence factors. At temperature T=0, the far-infrared absorption edge is, as expected, determined by the smallest gap. However, the large thermal background may mask this edge at finite temperatures and instead the secondary absorption edges found at \ensuremathΔi+\ensuremathΔj may become most prominent. At finite T, if certain interband matrix elements are large, there may also be absorption peaks at the gap difference frequencies |\ensuremathΔi\ensuremath-\ensuremathΔj|/\ensuremath\Elzxh. We discuss the effect of sample quality on the measured spectra and the possible relation of these predictions to the recent infrared absorption measurement on MgB2.