Polaron origin for anharmonicity of the axial oxygen in YBa sub 2 Cu sub 3 O sub 7

Journal Article · Mon May 25 04:00:00 EDT 1992 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.68.3236· OSTI ID:7039737

Mustre de Leon, J; Batistic, I; Bishop, A R; Conradson, S D; Trugman, S A ^[1]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

We present exact diagonalization results of an electron-phonon model Hamiltonian for the O(4)-Cu(1)-O(4) cluster in YBa{sub 2}Cu{sub 3}O{sub 7}. For large enough electron--infrared-phonon coupling the motion of holes and ions becomes strongly correlated, i.e., polaronic, leading to a double-well structure for the infrared mode, as encountered in x-ray-absorption fine structure. In contrast, the associated Raman mode shows a single-well behavior even for large electron--Raman-phonon coupling. The appearance of polarons accompanies nonadiabatic behavior yielding optical spectroscopy predictions differing from those obtained from harmonic or anharmonic lattice dynamics models.

• OSTI ID: 7039737
• Journal Information: Physical Review Letters; (United States), Journal Name: Physical Review Letters; (United States) Vol. 68:21; ISSN PRLTA; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
COUPLING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
ELECTRON-PHONON COUPLING
ENERGY LEVELS
EXCITED STATES
HIGH-TC SUPERCONDUCTORS
INFRARED SPECTRA
LASER SPECTROSCOPY
OXIDES
OXYGEN COMPOUNDS
POLARONS
QUASI PARTICLES
RAMAN SPECTROSCOPY
SPECTRA
SPECTROSCOPY
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
VIBRATIONAL STATES
YTTRIUM COMPOUNDS
YTTRIUM OXIDES