Pairing in CuO/sub 2/ driven by exchange interactions between carriers and localized Cu spins

Conference · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6017258

Stechel, E. B.; Jennison, D. R.

Calculations using a realistic multi-band extended Hubbard Hamiltonian, which correctly describes the Heisenberg excitation spectrum and superexchange energy of the insulating phase of CuO/sub 2/, show that the two largest energies relating to the carrier quasiparticle are the carrier bandwidth (>5 eV) and an exceptionally large (/approximately/3 eV times a density of states factor as in an RKKY interaction) effective exchange energy between a delocalized carrier hole and a localized Cu hole. The Cu holes are found to remain localized in the superconducting materials. Calculations using a model pairing Hamiltonian show that this exchange energy induces (through partial spin-polarization of the Cu holes) an attraction between carriers. This attraction is strong enough to overcome a realistic Coulomb repulsion, hence leading to net attractive pairing. Triplet p-wave (or possibly singlet d-wave) pairing is implied. 7 refs.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6017258
• Report Number(s): SAND-89-1546C; CONF-890718-2; ON: DE89014488
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
BINDING ENERGY
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ENERGY
HAMILTONIANS
MATHEMATICAL OPERATORS
ORIENTATION
OXIDES
OXYGEN COMPOUNDS
P WAVES
PAIRING ENERGY
PARTIAL WAVES
QUANTUM OPERATORS
SPIN ORIENTATION
TRANSITION ELEMENT COMPOUNDS