title: Charge and spin orderings in triangular t-J-V model with quarter filling: application to Na(0.5)CoO(2).
abstract: We investigated the ground state (GS) properties of the single-orbital t-J-V model in a quarter-filling two-dimensional triangular lattice with the slave-boson mean-field approach. We found that the charge ordering (CO) and spin ordering arising from the spin exchange interaction J competes with that from the inter-site Coulomb interaction V. For comparatively large J, the stable GS is insulating with striped CO and antiferromagnetic ordering, avoiding the homogeneous frustrated phase. Accompanying the insulating CO phase, a small insulating gap is opened. Within a reasonable J and V parameter region, our results are consistent with the recent neutron scattering experiments in Na(0.5)CoO(2), which possibly elucidate its CO, magnetic and other GS properties.
authors.affiliation: Department of Electronics, College of Information Technical Science, Nankai University, Tianjin 300071, People's Republic of China. Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, PO Box 1129, Hefei 230031, People's Republic of China.
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Wang
authors.forename: Ya Hui
authors.initials: YH
authors.lastname: Cheng
authors.forename: Feng
authors.initials: F
authors.lastname: Lu
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Liang-Jian
authors.initials: LJ
authors.lastname: Zou