Observation of an extended'' Van Hove singularity in YBa[sub 2]Cu[sub 4]O[sub 8] by ultrahigh energy resolution angle-resolved photoemission

Journal Article · Mon Dec 12 00:00:00 EST 1994 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.73.3302· OSTI ID:6620958

Gofron, K; Campuzano, J C; Abrikosov, A A; Lindroos, M; Bansil, A; Ding, H; Koelling, D; Dabrowski, B ^[1]

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1. Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States) Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607 (United States) Physics Department, Northeastern University, Boston, Massachusetts 02115 (United States) Physics Department, Tampere University of Technology, Tampere (Finland) Physics Department, Northern Illinois University, DeKalb, Illinois 60115 (United States)

We characterize the nature of the Van Hove singularity near the Fermi energy ([ital E][sub [ital F]]) in YBa[sub 2]Cu[sub 4]O[sub 8] using ultrahigh energy resolution (10 meV) angle-resolved photoemission spectroscopy, together with corresponding first-principles spectra intensity computations. The singularity, related to CuO[sub 2] planes, is located about 19 meV below [ital E][sub [ital F]] at the [ital Y] point in the Brillouin zone and arises from a band which is nearly dispersionless along the [Gamma] to [ital Y] direction. Such an extended'' saddle point would render the band structure quasi-1D and yield a power law divergence in the density of states, allowing the occurrence of [ital T][sub [ital c]]'s of order 100 K even in a weak coupling BCS scheme.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6620958
• Journal Information: Physical Review Letters; (United States), Vol. 73:24; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BARIUM OXIDES
PHOTOEMISSION
COPPER OXIDES
HIGH-TC SUPERCONDUCTORS
YTTRIUM OXIDES
ANGULAR DISTRIBUTION
ELECTRONIC STRUCTURE
FERMI LEVEL
SINGULARITY
TEMPERATURE DEPENDENCE
VAN HOVE THEORY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
DISTRIBUTION
EMISSION
ENERGY LEVELS
OXIDES
OXYGEN COMPOUNDS
SECONDARY EMISSION
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360207* - Ceramics
Cermets
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665100 - Nuclear Techniques in Condensed Matter Physics - (1992-)