Finite bandwidth effects on the transition temperature and NMR relaxation rate of impure superconductors

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.8591· OSTI ID:279807

Choi, H ^[1]

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1. Department of Physics, Sung Kyun Kwan University, Suwon 440-746 (Korea)

We study the thermodynamic properties of impure superconductors by explicitly taking into consideration the finiteness of electronic bandwidths within the phonon-mediated Eliashberg formalism. For a finite electronic bandwidth, the superconducting transition temperature, {ital T}{sub {ital c}}, is suppressed by nonmagnetic impurity scatterings. This is a consequence of a reduction in the effective electron-phonon coupling, {lambda}{sub eff}. The reduced {lambda}{sub eff} is reflected in the observation that the coherence peak in 1/({ital T}{sub 1}{ital T}), where {ital T}{sub 1} is the nuclear spin-lattice relaxation time and {ital T} is the temperature, is enhanced by impurity scatterings for a finite bandwidth. Calculations are presented for {ital T}{sub {ital c}} and 1/({ital T}{sub 1}{ital T}) as bandwidths and impurity scattering rates are varied. Implications for doped C{sub 60} superconductors are discussed in connection with {ital T}{sub {ital c}} and 1/{ital T}{sub 1} measurements. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 279807
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 13 Vol. 53; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BANDWIDTH
DOPED MATERIALS
ELECTRON-PHONON COUPLING
FULLERENES
GORKOV-ELIASHBERG THEORY
NMR SPECTRA
RELAXATION TIME
SPIN-LATTICE RELAXATION
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE