Hole motion in the t - J and Hubbard models: Effect of a next-nearest-neighbor hopping

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.42.6222· OSTI ID:6096759

Gagliano, E; Bacci, S; Dagotto, E ^[1]

---

1. Physics Department, University of Illinois at Urbana-Champaign, Urbana, IL (USA) Material Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL (USA)

Using exact diagonalization techniques, we study one dynamical hole in the two-dimensional {ital t}-{ital J} and Hubbard models on a square lattice including a next-nearest-neighbor hopping {ital t}{prime}. We present the phase diagram in the parameter space ({ital J}/{ital t},{ital t}{prime}/{ital t}), discussing the ground-state properties of the hole. At {ital J}=0, a crossing of levels exists at some value of {ital t}{prime} separating a ferromagnetic from an antiferromagnetic ground state. For nonzero {ital J}, at least four different regions appear where the system behaves like an antiferromagnet or a (not fully saturated) ferromagnet. We study the quasiparticle behavior of the hole, showing that for small values of {vert bar}{ital t}{prime}{vert bar} the previously presented string picture is still valid. We also find that, for a realistic set of parameters derived from the Cu-O Hamiltonian, the hole has momentum ({pi}/2,{pi}/2), suggesting an enhancement of the {ital p}-wave superconducting mode due to the second-neighbor interactions in the spin-bag picture. Results for the {ital t}-{ital t}{prime}-{ital U} model are also discussed with conclusions similar to those of the {ital t}-{ital t}{prime}-{ital J} model. In general we found that {ital t}{prime}=0 is not a singular point of these models.

• DOE Contract Number: FG03-85ER45197
• OSTI ID: 6096759
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 42:10; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

656100* -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIFERROMAGNETISM
CRYSTAL MODELS
DIAGRAMS
ENERGY LEVELS
FERROMAGNETISM
GROUND STATES
HEISENBERG MODEL
HIGH-TC SUPERCONDUCTORS
HOLE MOBILITY
MAGNETISM
MATHEMATICAL MODELS
MATHEMATICS
MOBILITY
NUMERICAL ANALYSIS
PHASE DIAGRAMS
SUPERCONDUCTORS
TWO-DIMENSIONAL CALCULATIONS