Correlation effects on the doped triangular lattice in view of the physics of sodium-rich Na${}_x$CoO${}_2$

Abstract

The peculiar correlation effects on the triangular lattice are studied by means of the rotationally invariant slave boson method in a cellular cluster approach. Hence nonlocal correlations are included in a short-range regime. Their impact for the single-band Hubbard model is studied at half filling, i.e., on the Mott transition, and with doping. Using the realistic band structure of Na${}_x$CoO${}_2$, we may also shed light on the cobaltate physics for $x$$\ge$1/3, with the in-plane transition from antiferromagnetic tendencies towards the onset of ferromagnetism for a finite Hubbard $U$.

final version, some refinements

References in corpus (8)

• Rotationally-invariant slave-boson formalism and momentum dependence of the quasiparticle weight
• The Hubbard model on the triangular lattice: Spiral order and spin liquid
• Electronic Correlations in CoO2, the Parent Compound of Triangular Cobaltates
• Spin correlations and cobalt charge states: A new phase diagram of sodium cobaltates
• Phase Diagram of Na${}_x$CoO${}_2$ Studied by Gutzwiller Density Functional Theory
• Local moment, itinerancy and deviation from Fermi liquid behavior in Na${}_x$CoO${}_2$ for $0.71\le x\le 0.84$
• Itinerant and localized magnetism on the triangular lattice: sodium rich phases of Na${}_x$CoO${}_2$
• The origin of a${}_{1g}$ and e${}_g$' orderings in Na${}_x$CoO${}_2$