Effect of the three-site hopping term on the {ital t}-{ital J} model

Journal Article · Sat Jul 01 04:00:00 EDT 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.52.629· OSTI ID:76434

Ammon, B; Troyer, M; Tsunetsugu, H ^[1]

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1. Interdisziplinaeres Projektzentrum fuer Supercomputing, Eidgenoessische Technische Hochschule, CH-8092 Zuerich (Switzerland)

We have used exact diagonalization and quantum Monte Carlo methods to study the one-dimensional {ital t}-{ital J} model including the three-site hopping term derived from the strong-coupling limit of the Hubbard model. The three-site term may be important to superconducting correlations since it allows direct hopping of local singlet electron pairs. The phase diagram is determined for several values of the strength of the three-site term and compared with that of the {ital t}-{ital J} and Hubbard models. Phase separation, which exists in the {ital t}-{ital J} model, is suppressed. In the low electron density region the formation of local singlet electron pairs is enhanced, leading to stronger superconducting correlations even for values {ital J}/{ital t}{lt}2. A large spin gap region extends from low electron densities up to high densities. In the low hole density region the superconducting correlations are suppressed at {ital J}/{ital t}{gt}2.8 in spite of enhanced pair formation. This is because the three-site term, while enhancing the formation of electron pairs, leads to a repulsion between holes.

• OSTI ID: 76434
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 1 Vol. 52; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANALYTICAL SOLUTION
COMPUTERIZED SIMULATION
CRYSTAL MODELS
ELECTRON CORRELATION
ELECTRON-HOLE COUPLING
HIGH-TC SUPERCONDUCTORS
MONTE CARLO METHOD
ONE-DIMENSIONAL CALCULATIONS
PAIRING INTERACTIONS