Realistic electronic-structure calculations of magnetic insulators like La[sub 2]CuO[sub 4]

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1991

OSTI ID:6986227

Grant, J B

The phenomenon of high-temperature superconductivity in certain copper oxides has so far gone unexplained. This is largely due to a lack of understanding of the electronic structure of these doped charge-transfer insulators. Traditional electronic-structure techniques cannot adequately treat both the strong electron dispersion and the strong electron-electron Coulomb interactions present in the materials. A new approach, developed there, is applied to the insulating La[sub 2]CuO[sub 4] parent of the 40K superconductor La[sub 1.85]Sr[sub .15]CuO[sub 4]. The approach is based on solving effective, multi-band Hubbard Hamiltonians that describe only the important low-energy excitations of these systems. Self-consistent, unrestricted Hartree-Fock (UHF) wave functions are first calculated then used to generate a basis of (nonorthogonal) configurations in which limited configuration-interaction (CI) calculations provide corrections to the UHF electronic structure. Of the four compounds considered, only La[sub 2]CuO[sub 4] can be doped to high-temperature superconductivity. Therefore, the limited CI technique is tailored specifically for La[sub 2]CuO[sub 4] which has spin 1/2 antiferromagnetic ordering of localized holes on the Cu sites.

• Research Organization: California Univ., Davis, CA (United States)
• OSTI ID: 6986227
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ANTIFERROMAGNETISM
CHALCOGENIDES
CONFIGURATION INTERACTION
COPPER COMPOUNDS
COPPER OXIDES
DOPED MATERIALS
ELECTRONIC STRUCTURE
FUNCTIONS
HARTREE-FOCK METHOD
HIGH-TC SUPERCONDUCTORS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MAGNETISM
MATERIALS
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
WAVE FUNCTIONS