1998/10/02 by Matthias J. Graf, Graf, Matthias J.
Physics and Astronomy · #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #Superconductivity (cond-mat.supr-con) #Surface and Thin Film Phenomena #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.cond-mat/9810023
To appear in the Proceedings of the 1st International Conference on Quasiclassical Methods in Superconductivity, eds. D. Rainer and J.A. Sauls, Verditz, Austria (1998)
arxiv created 1998/10/02 · openalex publication_date 1998/10/02 · arxiv updated 2011/04/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We investigate the electronic transport coefficients in unconventional superconductors at low temperatures, where charge and heat transport are dominated by electron scattering from random lattice defects. We discuss the features of the pairing symmetry, Fermi surface, and excitation spectrum which are reflected in the low temperature heat transport. For temperatures kB T \la γ≪ Δ0, where γ is the bandwidth of impurity induced Andreev states, certain eigenvalues become \it universal, i.e., independent of the impurity concentration and phase shift. Deep in the superconducting phase (kB T \la γ) the Wiedemann-Franz law, with Sommerfeld's value of the Lorenz number, is recovered. We compare our results for theoretical models of unconventional superconductivity in high-Tc and heavy fermion superconductors with experiment. Our findings show that impurities are a sensitive probe of the low-energy excitation spectrum, and that the zero-temperature limit of the transport coefficients provides an important test of the order parameter symmetry.