Properties of lightly doped {ital t}-{ital J} two-leg ladders

Journal Article · Mon Jan 01 04:00:00 EST 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.251· OSTI ID:434491

Troyer, M ^[1]; Tsunetsugu, H ^[2]; Rice, T M ^[3]

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1. Interdisziplinaeres Projektzentrum fuer Supercomputing, Eidgenoessische Technische Hochschule, CH-8092 Zuerich, Switzerl
2. Interdisziplinaeres Projektzentrum fuer Supercomputing, Eidgenoessische Technische Hochschule, CH-8092 Zuerich (Switzerland)
3. Theoretische Physik, Eidgenoessische Technische Hochschule, CH-8093 Zuerich (Switzerland)

We have numerically investigated the doped {ital t}-{ital J} ladder using exact diagonalization. We have studied both the limit of strong interchain coupling and isotropic coupling. The ladder scales to the Luther-Emery liquid regime in the strong interchain coupling limit. In this strong coupling limit there is a simple picture of the excitation spectrum that can be continued to explain the behavior at isotropic coupling. At {ital J}=0 we have indications of a ferromagnetic ground state. At a large {ital J}/{ital t} the ladder is phase separated into holes and a Heisenberg ladder. At intermediate coupling the ground state shows hole pairing with a modified {ital d}-wave symmetry. The excitation spectrum separates into a limited number of quasiparticles which carry charge +{parallel}{ital e}{parallel} and spin 1/2 and a triplet magnon mode. At half filling the former vanish but the latter evolves continuously into the magnon band of the spin liquid. At low doping the quasiparticles form a dilute Fermi gas with a strong attraction but simultaneously the Fermi wave vector, as would be measured in photoemission, is large. The dynamical structure factors are calculated and are found to be very similar to calculations on two-dimensional clusters. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 434491
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 1 Vol. 53; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COLLECTIVE EXCITATIONS
CRYSTAL MODELS
FERROMAGNETISM
HIGH-TC SUPERCONDUCTORS
NUMERICAL SOLUTION
PHASE STUDIES
QUASI PARTICLES