Experimental study of the incoherent spectral weight in the photoemission spectra of the misfit cobaltate [Bi2Ba2O4][CoO2]2

Abstract

Previous ARPES experiments in NaxCoO2 reported both a strongly renormalized bandwidth near the Fermi level and moderately renormalized Fermi velocities, leaving it unclear whether the correlations are weak or strong and how they could be quantified. We explain why this situation occurs and solve the problem by extracting clearly the coherent and incoherent parts of the band crossing the Fermi level. We show that one can use their relative weight to estimate self-consistently the quasiparticle weight Z, which turns out to be very small Z=0.15 +/- 0.05. We suggest this method could be a reliable way to study the evolution of correlations in cobaltates and for comparison with other strongly correlated systems.

References in corpus (14)

• Fermi surface and quasiparticle dynamics of Na(x)CoO2 {x=0.7} investigated by Angle-Resolved Photoemission Spectroscopy
• Fermi surface evolution and Luttinger theorem in Na${}_x$CoO${}_2$: a systematic photoemission study
• ARPES on Na${}_{0.6}$CoO${}_2$: Fermi surface, extended flat dispersion, and unusual band splitting
• Anomalous high energy dispersion in photoemission spectra from insulating cuprates
• Low-lying quasiparticle states and hidden collective charge instabilities in parent cobaltate superconductors (NaxCoO2)
• The crucial importance of the $t_{2g}$--$e_g$ hybridization in transition metal oxides
• Complete d-Band Dispersion and the Mobile Fermion Scale in NaxCoO2
• Na Induced Correlations in Na${}_x$CoO${}_2$
• The low-energy ARPES and heat capacity of Na${}_{0.3}$CoO${}_2$: A DMFT study
• Direct observation of strong correlations near the band insulator regime of Bi misfit cobaltates
• Dynamical mean field theory of an effective three-band model for Na${}_x$CoO${}_2$
• Spin polaron theory for the photoemission spectra of layered cobaltates
• Spin fluctuations, magnetic long-range order and Fermi surface gapping in NaxCoO2
• Novel electronic structure induced by a highly strained oxide interface with incommensurate crystal fields

Cited by in corpus (7)

• Hallmark of strong electronic correlations in LaNiO${}_3$: photoemission kink and broadening of fully occupied bands
• Strong correlations enhanced by charge-ordering in highly doped cobaltates
• Effective Hamiltonian for transition-metal compounds. Application to Na_xCoO_2
• Magnetic field dependent specific heat and enhanced Wilson ratio in strongly correlated layered cobalt oxide
• Considerable non-local electronic correlations in strongly doped Na${}_x$CoO${}_2$
• ω/T scaling of the optical conductivity in strongly correlated layered cobalt oxide
• Anomalous band renormalization due to high energy $kink$ in the colossal thermoelectric material K${}_{0.65}$RhO${}_2$