Magnetic properties of spin-orbital polarons in lightly doped cobaltates

Abstract

We present a numerical treatment of a spin-orbital polaron model for Na_xCoO_2 at small hole concentration (0.7 < x < 1). We demonstrate how the polarons account for the peculiar magnetic properties of this layered compound: They explain the large susceptibility; their internal degrees of freedom lead both to a negative Curie-Weiss temperature and yet to a ferromagnetic intra-layer interaction, thereby resolving a puzzling contradiction between these observations. We make specific predictions on the momentum and energy location of excitations resulting from the internal degrees of freedom of the polaron, and discuss their impact on spin-wave damping.

arXiv comment4+ pages, 6 figures, accepted for publication in Phys. Rev. Lett

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Cited by in corpus (16)

• Orbitally induced string formation in the spin-orbital polarons
• Direct observation of strong correlations near the band insulator regime of Bi misfit cobaltates
• A unified origin for the 3D magnetism and superconductivity in Na${}_x$CoO${}_2$
• The origin of strong correlations and superconductivity in Na${}_x$CoO${}_2$
• Fingerprints of spin-orbital polarons and of their disorder in the photoemission spectra of doped Mott insulators with orbital degeneracy
• Itinerant and localized magnetism on the triangular lattice: sodium rich phases of Na${}_x$CoO${}_2$
• Spin polaron theory for the photoemission spectra of layered cobaltates
• Electron-phonon interaction in the lamellar cobaltate Na${}_x$CoO${}_2$
• Novel electronic structure induced by a highly strained oxide interface with incommensurate crystal fields
• Dual electronic states in thermoelectric cobalt oxide
• Origin of the electron disproportionation in the metallic sodium cobaltates
• Revisiting the crystal electric field of P2-NaxCoO2 for the intermediate spin state of Co3+
• Ferrimagnetic ordering and spin entropy of field-dependent intermediate spins in Na0.82CoO2
• Exact spectral function for hole-magnon coupling in the ferromagnetic CuO${}_3$-like chain
• Role of electronic correlations in the Fermi surface formation of Na${}_x$CoO${}_2$
• Enhanced low energy fluctuations and increasing out-of-plane coherence in vacancy ordered NaxCoO2