Magnetic impurities in a strongly coupled superconductor

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Awelewa, Samuel, Dzero, Maxim
Format: Preprint
Veröffentlicht: 2024
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866908613113544704
author Awelewa, Samuel
Dzero, Maxim
author_facet Awelewa, Samuel
Dzero, Maxim
contents We revisit certain aspects of a problem concerning the influence of carrier scattering induced by magnetic impurities in metals on their superconducting properties. Superconductivity is assumed to be driven by strong electron-phonon interaction. We use the self-consistent solution of the Nagaoka equations for the scattering matrix together with the Migdal-Eliashberg theory of superconductivity to compute the energy of the in-gap bound states, superconducting critical temperature and tunneling density of states for a wide range of values of the Kondo temperature and impurity concentrations. It is found that similar to the case of the weak coupling (BCS) superconductors there is only one pair of the bound states inside the gap as well as re-entrant superconductivity for the case of antiferromagnetic exchange coupling between the conduction electrons and magnetic impurities. In agreement with the earlier studies we find that the gapless superconductivity can be realized which in the case of antiferromagnetic exchange requires much smaller impurity concentration. Surprisingly, in contrast with the weakly coupled superconductors we find that superconducting transition exhibits two critical temperatures for the ferromagnetic exchange coupling.
format Preprint
id arxiv_https___arxiv_org_abs_2412_03646
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Magnetic impurities in a strongly coupled superconductor
Awelewa, Samuel
Dzero, Maxim
Superconductivity
Strongly Correlated Electrons
We revisit certain aspects of a problem concerning the influence of carrier scattering induced by magnetic impurities in metals on their superconducting properties. Superconductivity is assumed to be driven by strong electron-phonon interaction. We use the self-consistent solution of the Nagaoka equations for the scattering matrix together with the Migdal-Eliashberg theory of superconductivity to compute the energy of the in-gap bound states, superconducting critical temperature and tunneling density of states for a wide range of values of the Kondo temperature and impurity concentrations. It is found that similar to the case of the weak coupling (BCS) superconductors there is only one pair of the bound states inside the gap as well as re-entrant superconductivity for the case of antiferromagnetic exchange coupling between the conduction electrons and magnetic impurities. In agreement with the earlier studies we find that the gapless superconductivity can be realized which in the case of antiferromagnetic exchange requires much smaller impurity concentration. Surprisingly, in contrast with the weakly coupled superconductors we find that superconducting transition exhibits two critical temperatures for the ferromagnetic exchange coupling.
title Magnetic impurities in a strongly coupled superconductor
topic Superconductivity
Strongly Correlated Electrons
url https://arxiv.org/abs/2412.03646