van Gerven Oei W V, Tanasković D
Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia.
J Phys Condens Matter. 2020 May 12;32(32). doi: 10.1088/1361-648X/ab83b0.
Spin-flip scattering from magnetic impurities has a strong pair-breaking effect in-wave superconductors where increasing the concentration of impurities rapidly destroys superconductivity. For small Kondo temperaturethe destruction of superconductivity is preceded by the reentrant superconductivity at finite temperature range<<, while the normal phase reappears at<∼. Here we explore the superconducting phase in a periodic system modeled as the Anderson lattice with additional attractive on-site (Hubbard) interactionacting on the conduction band electrons. We solve the equations using dynamical mean field theory which incorporates Kondo physics, while the pairing interaction is treated on the static mean-field level. For large couplingwe find reentrant superconductivity which resembles the case with diluted impurities. However, we find evidence that reentrant superconductivity is here not a consequence of many-body correlations leading to the Kondo effect, but it rather stems from a competition between the single-particle hybridization and superconducting pairing. An insight into the spectral functions with in-gap structures is obtained from an approximate noninteracting dual model whose solution interpolates between several exact limits.
