Order and disorder in the triangular-lattice t-J-V model at 2/3 electron density

Abstract

Motivated by the recent discovery of superconductivity in Na${}_x$CoO${}_2\cdot y$H${}_2$O, we use series expansion methods and cluster mean-field theory to study spontaneous charge order, Neel order, ferromagnetic order, dimer order and phase-separation in the triangular-lattice t-J-V model at 2/3 electron density. We find that for t<0, the charge ordered state, with electrons preferentially occupying a honeycomb lattice, is very robust. Quite surprisingly, hopping to the third sublattice can even enhance Neel order. At large negative t and small V, the Nagaoka ferromagnetic state is obtained. For large positive t, charge and Neel order vanish below a critical V, giving rise to an itinerant antiferromagnetically correlated state.

4 pages, 5 figures

References in corpus (8)

• Charge-ordering, commensurability and metallicity in the phase diagram of layered Na(x)CoO(2)
• Exact spectra, spin susceptibilities and order parameter of the quantum Heisenberg antiferromagnet on the triangular lattice
• Superconductivity Phase Diagram of Na(x)CoO(2).1.3H(2)O
• An Electronic Model for $Co{O}_2$ layer based systems: Chiral RVB metal and Superconductivity
• Superconductivity in CoO${}_2$ Layers and the Resonating Valence Bond Mean Field Theory of the Triangular Lattice t-J model
• Doped t-J Model on a Triangular Lattice: Possible Application to Na${}_x$CoO${}_2\cdot y$H${}_2$0 and Na${}_{1-x}$TiO${}_2$
• Possible effects of charge frustration in Na${}_x$CoO${}_2$: bandwidth suppression, charge orders and resurrected RVB superconductivity
• Ferromagnetism in the Hubbard model: instability of the Nagaoka state on the triangular, honeycomb and kagome lattices

Cited by in corpus (8)

• Slave spin cluster mean field theory away from half-filling: Application to the Hubbard and the extended Hubbard Model
• Competition between charge and spin order in the $t-U-V$ extended Hubbard model on the triangular lattice
• Loop-Cluster Simulation of the $t$-$J$ Model on the Honeycomb Lattice
• Single-hole properties of the t-J model on the honeycomb lattice
• Systematic Effective Field Theory Investigation of Spiral Phases in Hole-Doped Antiferromagnets on the Honeycomb Lattice
• Effect of hole doping on the 120 degree order in the triangular lattice Hubbard model: A Hartree-Fock revisit
• Correlation-driven non-trivial phases in single bi-layer Kagome intermetallics
• Sea-Boson Analysis of the Infinite-U Hubbard Model