Theoretical calculation of the wave-vector- and frequency-dependent dielectric function of YBa sub 2 Cu sub 3 O sub 7

Journal Article · Tue Jan 01 00:00:00 EST 1991 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.43.383· OSTI ID:6258826

Chen, H; Callaway, J; Brener, N E ^[1]; Zou, Z ^[2]

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1. Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001 (US)
2. Department of Physics, University of Colorado, Boulder, Colorado 80309-0390 (US)

Real and imaginary parts of the dielectric function {epsilon}({omega},{bold q}) of YBa{sub 2}Cu{sub 3}O{sub 7} are calculated in the random-phase approximation, based on a parametrized tight-binding band structure. Only the contribution to the dielectric function from electronic interband transitions is considered. Prominent optical absorption peaks are found at 3.0, 2.3, and below 0.6 eV. For energy in the range 0.2--1.5 eV, we find that {epsilon}{sub 1} is negative in a very large region inside the {ital q}{sub {ital x}},{ital q}{sub {ital y}} plane. Detailed studies on these low-energy absorption peaks reveal that they are mainly associated with the interband charge excitations involving orbitals within the Cu-O plane. For optical properties ({ital q}=0), our results are compared with experimental data and previously reported theoretical calculations. There is a reasonably good agreement.

• OSTI ID: 6258826
• Journal Information: Physical Review, B: Condensed Matter; (USA), Vol. 43:1, Issue 1; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
DIELECTRIC PROPERTIES
COPPER OXIDES
YTTRIUM OXIDES
ELECTRON-ELECTRON COUPLING
ENERGY LEVELS
FREQUENCY DEPENDENCE
RANDOM PHASE APPROXIMATION
SUPERCONDUCTIVITY
WAVE FUNCTIONS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FUNCTIONS
OXIDES
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PHYSICAL PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360204* - Ceramics
Cermets
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