Relation of extended Van Hove singularities to high-temperature superconductivity within strong-coupling theory

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.50.9554· OSTI ID:7202924

Radtke, R J ^[1]; Norman, M R ^[2]

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1. Department of Physics and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States)
2. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

Recent angle-resolved photoemission (ARPES) experiments have indicated that the electronic dispersion in some of the cuprates possesses an extended saddle point near the Fermi level which gives rise to a density of states that diverges like a power law instead of the weaker logarithmic divergence usually considered. We investigate whether this strong singularity can give rise to high transition temperatures by computing the critical temperature [ital T][sub [ital c]] and isotope effect coefficient [alpha] within a strong-coupling Eliashberg theory which accounts for the full energy variation of the density of states. Using band structures extracted from ARPES measurements, we demonstrate that, while the weak-coupling solutions suggest a strong influence of the strength of the Van Hove singularity on [ital T][sub [ital c]] and [alpha], strong-coupling solutions show less sensitivity to the singularity strength and do not support the hypothesis that band-structure effects alone can account for either the large [ital T][sub [ital c]]'s or the different [ital T][sub [ital c]]'s within the copper oxide family. This conclusion is supported when our results are plotted as a function of the physically relevant self-consistent coupling constant, which shows universal behavior at very strong coupling.

• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 7202924
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 50:13; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ELECTRONIC STRUCTURE
GORKOV-ELIASHBERG THEORY
HIGH-TC SUPERCONDUCTORS
ISOTOPE EFFECTS
MATHEMATICAL MODELS
PARTICLE MODELS
PHYSICAL PROPERTIES
SINGULARITY
STRONG-COUPLING MODEL
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE