Electronic structure of CuO/sub 2/ sheets and spin-driven high-T/sub c/ superconductivity

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.4632· OSTI ID:6933603

Stechel, E B; Jennison, D R

Energy parameters for a CuO/sub 2/ sheet, taken to be prototypic of the high-temperature superconductors, are derived from semiempirical and ab initio sources. Intra-atomic Coulomb interactions (U/sub i/) are large, but interatomic Coulomb terms and direct oxygen-oxygen transfer integrals are also very important. These energies dictate a two-band extended Hubbard Hamiltonian which cannot obviously be simplified. With Cu(d/sup 10/)O(p/sup 6/) as the vacuum state, interatomic Coulomb interactions create a potential well resulting in hole localization when there is one hole per CuO/sub 2/ unit cell, so that the Cu(d/sup 9/) valence is dominant. A spin-(1/2 Heisenberg system thus exists independent of the presence of carriers due to the poor screening in these materials. We compute the Cu-Cu superexchange energy J from the other parameters and find good agreement with empirically derived values, provided the inclusion direct Cu-O exchange. Because of the relatively large value of J, we assume local antiferromagnetic (AF) order. Itinerent carriers exist on the oxygen sublattice because of the large Cu U/sub d/.

• Research Organization: Solid State Theory Division 1151, Sandia National Laboratories, Albuquerque, New Mexico 87185
• OSTI ID: 6933603
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:7; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANGULAR MOMENTUM
CHALCOGENIDES
CHARGE CARRIERS
COPPER COMPOUNDS
COPPER OXIDES
ELECTRONIC STRUCTURE
INTERACTIONS
INTERATOMIC FORCES
OXIDES
OXYGEN COMPOUNDS
PAIRING INTERACTIONS
PARTICLE PROPERTIES
SPIN
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
VALENCE