Spin polaron theory for the photoemission spectra of layered cobaltates

Abstract

Recently, strong reduction of the quasiparticle peaks and pronounced incoherent structures have been observed in the photoemission spectra of layered cobaltates. Surprisingly, these many-body effects are found to increase near the band insulator regime. We explain these unexpected observations in terms of a novel spin-polaron model for CoO_2 planes which is based on a fact of the spin-state quasidegeneracy of Co^{3+} ions in oxides. Scattering of the photoholes on spin-state fluctuations suppresses their coherent motion. The observed ``peak-dip-hump'' type lineshapes are well reproduced by the theory.

arXiv comment4 pages, 4 figures

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Cited by in corpus (6)

• Experimental study of the incoherent spectral weight in the photoemission spectra of the misfit cobaltate [Bi2Ba2O4][CoO2]2
• Metal-nonmetal transition in LixCoO2 thin film and thermopower enhancement at high Li concentration
• Origin of the electron disproportionation in the metallic sodium cobaltates
• Enhanced low energy fluctuations and increasing out-of-plane coherence in vacancy ordered NaxCoO2
• Superconductivity in the spin-state crossover materials: Nickelates with planar-coordinated low-spin Ni${}^{2+}$ ions
• Magnetic polarons due to spin-length fluctuations in ${\mathbf{d}}^4$ spin-orbit Mott systems