Enhancement of the electron-lattice interaction due to strong electron correlation

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.49.8944· OSTI ID:5090838

Ishihara, S ^[1]; Egami, T ^[2]; Tachiki, M ^[1]

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1. Institute for Materials Research, Tohoku University, Sendai 980 (Japan)
2. Institute for Materials Research, Tohoku University, Sendai 980 (Japan) Department of Materials Science and Engineering and Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6272 (United States)

Effects of strong electron correlation on the electron-lattice interaction are studied by means of the exact diagonalization method for a finite-size cluster system. A simple two-component tight-binding Hamiltonian with the intrasite and intersite Coulomb repulsions is adopted. Upon changing the correlation energy ([ital U]) and the energy-level separation ([Delta]), the system is found to undergo a transition between the ionic insulating phase and the Mott insulating phase. Near the phase boundary the system becomes unstable under a small perturbation and a dramatic enhancement of the electron-lattice interaction is observed. Spin and charge properties are also strongly affected by the lattice distortion in a crossover region. The implication of the calculated results to the origins of the displacive-type ferroelectricity and the superconductivity in transition-metal oxides is discussed.

• OSTI ID: 5090838
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 49:13; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665400* -- Quantum Physics Aspects of Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHALCOGENIDES
CORRELATIONS
COUPLING
ELECTRON CORRELATION
ELECTRON-PHONON COUPLING
FERROELECTRIC MATERIALS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS