title: Theory of carrier concentration-dependent electronic behavior in layered cobaltates.
abstract: A natural explanation for the carrier concentration-dependent electronic behavior in the layered cobaltates emerges within correlated-electron Hamiltonians with finite on-site and significant nearest neighbor hole-hole Coulomb repulsions. The nearest neighbor repulsion decreases hole double occupancy below hole density 1/3, but increases the same at higher hole densities. Our conclusion is valid for both single-band and three-band extended Hubbard Hamiltonians, and sheds light on concentration dependent e'(g) hole occupancy within the latter.
authors.affiliation: Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: R T
authors.initials: RT
authors.lastname: Clay
authors.forename: S
authors.initials: S
authors.lastname: Mazumdar