Raman spectrum of superconducting oxides

Journal Article · Wed Jan 01 00:00:00 EST 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.45.347· OSTI ID:5071097

Virosztek, A ^[1]; Ruvalds, J ^[2]

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1. Central Research Institute for Physics, H-1525 Budapest 114, P.O. Box 49 (Hungary)
2. Physics Department, University of Virginia, Charlottesville, Virginia 22901 (United States)

The anomalous electronic Raman scattering in the normal state of various cuprates extends smoothly to an energy of 1 eV. This behavior is shown to be in accord with the frequency-dependent damping caused by electron-electron scattering between nearly parallel (i.e., nested'') sections of the Fermi surface. Intermediate on-site Coulomb repulsion is found to be compatible with the data, whereas the long-range Coulomb coupling is ineffective in the small-momentum-transfer limit. The matrix element for the scattering process is attributed to energy-density fluctuations for anisotropic Fermi surfaces. By contrast, conventional density-fluctuation processes for parabolic energy bands are several orders of magnitude smaller and restricted to a narrow frequency range because of charge conservation and the Pauli exclusion principle. A surprising proportionality between the Raman line shape and the optical conductivity is derived in the nesting approximation. Evidence for such behavior is established by fits to the Raman spectra of YBa{sub 2}Cu{sub 3}O{sub 7} and Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} using electron-electron coupling and energy-cutoff values previously obtained from our analysis of the optical conductivity and reflectance data. Similar electronic spectra should appear in other metals with nested Fermi surfaces, such as chromium and various rare-earth metals.

• DOE Contract Number: FG05-84ER45113
• OSTI ID: 5071097
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 45:1; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
RAMAN SPECTRA
BISMUTH OXIDES
CALCIUM OXIDES
COPPER OXIDES
HIGH-TC SUPERCONDUCTORS
STRONTIUM OXIDES
YTTRIUM OXIDES
CUPRATES
ELECTRON-ELECTRON INTERACTIONS
FERMI GAS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BISMUTH COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
FLUIDS
GASES
INTERACTIONS
LEPTON-LEPTON INTERACTIONS
OXIDES
OXYGEN COMPOUNDS
PARTICLE INTERACTIONS
SPECTRA
STRONTIUM COMPOUNDS
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties