Abstract
The exact ground-state energy E0 is calculated for a one-dimensional copper-oxide model defined on a ring of finite length L, threaded by an external flux . It includes on-site and nearest-neighbor intersite Coulomb repulsion V, as well as a nonzero bare oxide gap 0 between the orbitals in the unit cell. The correlation exponent K of the corresponding low-energy Hamiltonian shows that singlet (extended s-wave) superconductivity has the most rapidly diverging susceptibility as T0 (K>1). This superconducting phase is located close to a phase-separation instability of the model, indicated by K. Longer range of the Coulomb interaction tends to frustrate phase separation, enhances the range of V for which K>1, and slightly broadens the regime of V where 1<K<.
Original language | English (US) |
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Pages (from-to) | 553-560 |
Number of pages | 8 |
Journal | Physical Review B |
Volume | 51 |
Issue number | 1 |
DOIs | |
State | Published - 1995 |
Externally published | Yes |
ASJC Scopus subject areas
- Condensed Matter Physics