Strong correlations enhanced by charge-ordering in highly doped cobaltates

Abstract

We present an explanation for the puzzling spectral and transport properties of layered cobaltates close to the band-insulator limit, which relies on the key effect of charge ordering. Blocking a significant fraction of the lattice sites deeply modifies the electronic structure in a way that is shown to be quantitatively consistent with photoemission experiments. It also makes the system highly sensitive to interactions (especially to intersite ones), hence accounting for the strong correlations effects observed in this regime, such as the high effective mass and quasiparticle scattering rate. These conclusions are supported by a theoretical study of an extended Hubbard model with a realistic band structure on an effective kagomè lattice.

4+ pages, 3 figures

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Cited by in corpus (11)

• Multi-orbital physics in Fermi liquids prone to magnetic order
• Competing orders in Na${}_x$CoO${}_2$ from strong correlations on a two-particle level
• From basic properties to the Mott design of correlated delafossites
• 23Na NMR study of sodium order in NaxCoO2 with 22K Neel temperature
• Getting back to Na_xCoO_2: spectral and thermoelectric properties
• Unusual Mott transition associated with charge-order melting in BiNiO${}_3$ under pressure
• Evolution of Co charge disproportionation with Na order in Na${}_x$CoO${}_2$
• From Hubbard bands to spin-polaron excitations in the doped Mott material Na${}_x$CoO${}_2$
• Origin of the electron disproportionation in the metallic sodium cobaltates
• Multiorbital kinetic effects on charge ordering of frustrated electrons on the triangular lattice
• Ab-initio studying of spin states of sodium cobaltate Na${}_{2/3}$CoO${}_2$