We propose a configuration interaction mechanism that leads to hole pairs with zero repulsion energy which are exact eigenstates of the two-band Hubbard Hamiltonian. The two-hole pairs have 1B2(xy) symmetry and arise from degenerate states at the Fermi level; we show that they must exist independently of the band filling. To discuss the possible relevance of these states to the problem of pairing in high-Tc superconductors we solve five- and nine-site model clusters with four holes. The quasiparticles become dressed by the interaction with the background holes and get paired with a set of valence band parameters well established for high-Tc cuprates. We predict a number of important experimental facts such as binding energies of the correct order of magnitude, the 1B1 (x2 - y2) symmetry of the order parameter and the singlet-triplet energy separation of the Cooper pairs.

Cini M., B.A. (1996). Two-hole quasiparticles and pairing in the Hubbard model of high-Tc superconducting cuprates. JOURNAL OF PHYSICS. CONDENSED MATTER, 8(17).

Two-hole quasiparticles and pairing in the Hubbard model of high-Tc superconducting cuprates

CINI, MICHELE;BALZAROTTI, ADALBERTO
1996

Abstract

We propose a configuration interaction mechanism that leads to hole pairs with zero repulsion energy which are exact eigenstates of the two-band Hubbard Hamiltonian. The two-hole pairs have 1B2(xy) symmetry and arise from degenerate states at the Fermi level; we show that they must exist independently of the band filling. To discuss the possible relevance of these states to the problem of pairing in high-Tc superconductors we solve five- and nine-site model clusters with four holes. The quasiparticles become dressed by the interaction with the background holes and get paired with a set of valence band parameters well established for high-Tc cuprates. We predict a number of important experimental facts such as binding energies of the correct order of magnitude, the 1B1 (x2 - y2) symmetry of the order parameter and the singlet-triplet energy separation of the Cooper pairs.
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore FIS/03 - Fisica della Materia
English
Con Impact Factor ISI
Band structure; Binding energy; Crystal symmetry; Eigenvalues and eigenfunctions; Fermi level; High temperature superconductors; Mathematical models; Cooper pairs; Eigenstates; Hole pairs; Hubbard model; Quasiparticles; Singlet triplet energy separation; Two band Hubbard Hamiltonian; Valence band; Oxide superconductors
Cini M., B.A. (1996). Two-hole quasiparticles and pairing in the Hubbard model of high-Tc superconducting cuprates. JOURNAL OF PHYSICS. CONDENSED MATTER, 8(17).
Cini, M; Balzarotti, A
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2108/58632
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