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Effects of Mass Enhancement on Cooper Pairing in Heavy-Fermion Superconductors
Abstract With m* ≈ 200 me (including in superconductors CeCu2Si2, UBe13, and UPt3) due mainly to many-body enhancement rather than a band structure effect, as confirmed recently by deHaas-van Alphen experiments on CeCu6 and UPt 3 1,2 , effects of the mass enhancement taken alone will be shown to be: (a) the coulomb pseudopotential μ* operating in a frequency range a few times the Debye frequency ωD is as usual much smaller than μ operating in a much larger range EF, where EF is of usual magnitude; (b) “Migdal’s theorem” holds for usual electron-phonon interactions and for any interaction operating within a frequency range comparable to ωD or smaller; and (c) the usual coulomb and phonon-mediated electron-electron interactions cannot be causing the superconductivity. Conditions (a) and (b) occur rather than intuitive results expected if m* were a band mass because enhancement of the quasiparticle density of states by many-body effects does not mean any enhancement at all of the electron density of states.
Effects of Mass Enhancement on Cooper Pairing in Heavy-Fermion Superconductors
Abstract With m* ≈ 200 me (including in superconductors CeCu2Si2, UBe13, and UPt3) due mainly to many-body enhancement rather than a band structure effect, as confirmed recently by deHaas-van Alphen experiments on CeCu6 and UPt 3 1,2 , effects of the mass enhancement taken alone will be shown to be: (a) the coulomb pseudopotential μ* operating in a frequency range a few times the Debye frequency ωD is as usual much smaller than μ operating in a much larger range EF, where EF is of usual magnitude; (b) “Migdal’s theorem” holds for usual electron-phonon interactions and for any interaction operating within a frequency range comparable to ωD or smaller; and (c) the usual coulomb and phonon-mediated electron-electron interactions cannot be causing the superconductivity. Conditions (a) and (b) occur rather than intuitive results expected if m* were a band mass because enhancement of the quasiparticle density of states by many-body effects does not mean any enhancement at all of the electron density of states.
Effects of Mass Enhancement on Cooper Pairing in Heavy-Fermion Superconductors
Fenton, E. W. (Autor:in)
Novel Superconductivity ; 279-285
01.01.1987
7 pages
Aufsatz/Kapitel (Buch)
Elektronische Ressource
Englisch
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