Optical Properties and Correlation Effects in NaxCoO2

Abstract

We have calculated the optical spectra of Na${}_x$CoO${}_2$ for $x$=0.3, 0.5, and 0.7 within the LDA. We compare our results to available experimental data and show that the important features and trends are reproduced well, but there is a nearly uniform shift of peak positions and poor agreement in intensities. We show, through application of a simple model, that these differences can be attributed to overhybridization between Co and O orbitals and spin fluctuations which renormalize the bandwidth. Applying the LDA+U procedure shifts the optical peaks further from their experimental locations, indicating that this method of incorporating correlation effects is ill-suited for the case NaxCoO2.

References in corpus (14)

• Spin entropy as the likely source of enhanced thermopower in $\rm\bf Na_xCo_2O_4
• Charge-ordering, commensurability and metallicity in the phase diagram of layered Na(x)CoO(2)
• Fermi surface and quasiparticle dynamics of Na(x)CoO2 {x=0.7} investigated by Angle-Resolved Photoemission Spectroscopy
• ARPES on Na${}_{0.6}$CoO${}_2$: Fermi surface, extended flat dispersion, and unusual band splitting
• Charge Disproportionation and Spin Ordering Tendencies in Na(x)CoO2
• Giant electron-electron scattering in the Fermi-liquid state of Na_0.7CoO_2
• Bulk antiferromagnetism in $\mathbf{N}{\mathbf{a}}_{0.82}\mathbf{Co}{\mathbf{O}}_2$ single crystals
• Ferromagnetic in-plane spin fluctuations in NaxCoO2 observed by neutron inelastic scattering
• Nesting, spin-fluctuations, and odd-gap superconductivity in NaxCoO2 yH2O
• Charge ordering and magneto-polarons in Na${}_{0.82}$CoO${}_2$
• Infrared probe of the electronic structure and charge dynamics in Na${}_{0.7}$CoO${}_2$
• The infrared spectrum of Na_0.57CoO_2
• A Tight-Binding Investigation of the NaxCoO2 Fermi Surface
• Optical evidence for the proximity to a spin-density-wave metallic state in Na${}_{0.7}$CoO${}_2$

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• An ab-initio evaluation of the local effective interactions in the superconducting compound $Na\_0.35CoO\_2-1.3H\_2O$
• Colossal Thermoelectric Power Factor in K${}_{7/8}$RhO${}_2$
• Electron-boson mode coupling and the pseudogap of Na${}_x$CoO${}_2$ by infrared spectroscopy
• Optical Study of the Electronic Structure and Correlation Effects in K0.49RhO2
• Competing magnetic orders in quantum critical Sr${}_3$Ru${}_2$O${}_7$
• Revisiting the crystal electric field of P2-NaxCoO2 for the intermediate spin state of Co3+
• Influence of water intercalation on the electronic structure of the hydrated Na0.3CoO2.yH2O using a local spin density approximation