2007/12/11 by Yue Zou, Israel Klich, Gil Refael · 1 citation
Materials Science · Mathematics · Physics and Astronomy · #BCS theory #Coherence (philosophical gambling strategy) #Coherence length #Condensed matter physics #Coupling (piping) #Coupling constant #Energy (signal processing) #Homogeneous #Iron-based superconductors research #Length scale #Limit (mathematics) #Materials science #Mathematical analysis #Mathematics #Mean field theory #Pairing #Phase (matter) #Phase coherence #Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum mechanics #Superconducting coherence length #Superconductivity #Thermodynamics #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.77.144523
published as Phys. Rev. B 77, 144523 (2008) · 12 pages, 14 figures
arxiv created 2007/12/11 · openalex publication_date 2008/04/25 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We investigate the influence of inhomogeneity in the pairing coupling constant U(\stackrelPr) on dirty BCS superconductors, focusing on Tc, the order parameter \ensuremathΔ(\stackrelPr), and the energy gap Eg(\stackrelPr). Within mean-field theory, we find that when the length scale of the inhomogeneity is comparable to or larger than the coherence length, the ratio 2Eg∕Tc is significantly reduced from that of a homogeneous superconductor, while in the opposite limit, this ratio stays unmodified. In two dimensions, when strong phase fluctuations are included, the Kosterlitz-Thouless temperature TKT is also studied. We find that when the inhomogeneity length scale is much larger than the coherence length, 2Eg∕TKT can be larger than the usual BCS value. We use our results to qualitatively explain recent experimental observation of a surprisingly low value of 2Eg∕Tc in thin films.