Finite-temperature real-energy-axis solutions of the isotropic Eliashberg integral equations

Journal Article · Sun Sep 01 04:00:00 EDT 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.54.6648· OSTI ID:383260

Holcomb, M J ^[1]

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1. Departments of Chemistry and Physics, Stanford University, Stanford, California 94305 (United States)

A fast, efficient algorithm has been developed for calculating the finite-temperature real-energy-axis solutions of the Eliashberg integral equations for an arbitrary form of the electron-boson coupling function and Coulomb repulsion. Using this algorithm, the complex superconducting gap function {Delta}({omega},{ital T}), and the complex renormalization function {ital Z}({omega},{ital T}), have been obtained for a variety of forms of the electron-boson coupling spectrum. In addition, by calculating {Delta}({omega},{ital T}) at finite temperatures, the superconducting critical temperature {ital T}{sub {ital c}} has been obtained for a variety of model systems. These results compare well with the approximate analytic expression derived by Allen and Dynes for values of {lambda} less than 0.75. The solution of the Eliashberg equations has also been obtained for a model in which there are two well separated peaks in the electron-phonon coupling spectrum. This form of coupling spectrum is found to be particularly effective in raising the {ital T}{sub {ital c}} of the model system. Further, this model has been extended and the solution of the Eliashberg equations has been obtained with an electron-boson coupling spectrum consisting of both an electron-phonon component and a high-energy electronic electron-boson component. This form of the electron-boson coupling function may have special significance in the field of high-temperature superconductivity. {copyright} {ital 1996 The American Physical Society.}

• DOE Contract Number: FG03-86ER45245
• OSTI ID: 383260
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 9 Vol. 54; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ALGORITHMS
BOSONS
COULOMB FIELD
ELECTRON-PHONON COUPLING
ENERGY GAP
GORKOV-ELIASHBERG THEORY
HIGH-TC SUPERCONDUCTORS
INTEGRAL EQUATIONS
SUPERCONDUCTIVITY