Low-lying quasiparticle states and hidden collective charge instabilities in parent cobaltate superconductors (NaxCoO2)

Abstract

We report a state-of-the-art photoemission (ARPES) study of high quality single crystals of the NaxCoO2 series focusing on the fine details of the low-energy states. The Fermi velocity is found to be small (< 0.5 eV.A) and only weakly anisotropic over the Fermi surface at all dopings setting the size of the pair wavefunction to be on the order of 10-20 nanometers. In the low doping regime the exchange inter-layer splitting vanishes and two dimensional collective instabilities such as 120-type fluctuations become kinematically allowed. Our results suggest that the unusually small Fermi velocity and the unique symmetry of kinematic instabilities distinguish cobaltates from other unconventional oxide superconductors such as the cuprates or the ruthenates.

arXiv commentAccepted for publication in Phys. Rev. Lett. (2006)

References in corpus (13)

• Angle-resolved photoemission spectroscopy of the cuprate superconductors
• Charge-ordering, commensurability and metallicity in the phase diagram of layered Na(x)CoO(2)
• Bilayer Splitting in the Electronic Structure of Heavily Overdoped Bi2Sr2CaCu2O8+d
• Fermi surface and quasiparticle dynamics of Na(x)CoO2 {x=0.7} investigated by Angle-Resolved Photoemission Spectroscopy
• Coupling between electronic and structural degrees of freedom in the triangular lattice conductor NaxCoO2
• Magnetic ordering and spin waves in $\mathbf{N}{\mathbf{a}}_{0.82}\mathbf{Co}{\mathbf{O}}_2$
• Fermi surface evolution and Luttinger theorem in Na${}_x$CoO${}_2$: a systematic photoemission study
• Doubling of the bands in overdoped Bi2Sr2CaCu2O8-probable evidence for c-axis bilayer coupling
• Electronic structure of MgB${}_2$ from angle-resolved photoemission spectroscopy
• Momentum anisotropy of the scattering rate in cuprate superconductors
• Non-magnetic insulator state in Na1CoO2 and phase separation of Na vacancies
• Study of the triangular lattice tV model near x=1/3
• Muon Spin Relaxation Measurements in Na_xCoO_2*yH_2O

Cited by in corpus (43)

• Observation of topological order in a Superconducting doped topological insulator (based on the Bi2Se3 class)
• Emergence of Fermi pockets in an excitonic CDW melted novel superconductor
• Complete d-Band Dispersion and the Mobile Fermion Scale in NaxCoO2
• Exact Diagonalization Dynamical Mean Field Theory for Multi-Band Materials: Effect of Coulomb correlations on the Fermi surface of Na_0.3CoO_2
• Discontinuous Lifshitz Transition Achieved by Band-Filling Control in NaxCoO2
• Spin-orbital groundstates of Superconducting doped topological insulators (A Majorana Platform)
• Phase Diagram of Na${}_x$CoO${}_2$ Studied by Gutzwiller Density Functional Theory
• Elliptical hole pockets in the Fermi surfaces of unhydrated and hydrated sodium cobalt oxides
• Competing orders in Na${}_x$CoO${}_2$ from strong correlations on a two-particle level
• Comment on " Low-Lying Quasiparticle States and Hidden Collective Charge Instabilities in Parent Cobaltate Superconductors"
• Local moment, itinerancy and deviation from Fermi liquid behavior in Na${}_x$CoO${}_2$ for $0.71\le x\le 0.84$
• The low-energy ARPES and heat capacity of Na${}_{0.3}$CoO${}_2$: A DMFT study
• Mottness on a triangular lattice
• Direct observation of strong correlations near the band insulator regime of Bi misfit cobaltates
• Itinerant in-plane magnetic fluctuations and many-body correlations in Na${}_x$CoO${}_2$
• GdI_2: A New Ferromagnetic Excitonic Solid?
• A unified origin for the 3D magnetism and superconductivity in Na${}_x$CoO${}_2$
• Fermiology via the electron momentum distribution
• Raman scattering for triangular lattices spin-1/2 Heisenberg antiferromagnets
• An extended Falicov-Kimball model on a triangular lattice
• Experimental study of the incoherent spectral weight in the photoemission spectra of the misfit cobaltate [Bi2Ba2O4][CoO2]2
• Strong correlations enhanced by charge-ordering in highly doped cobaltates
• Itinerant and localized magnetism on the triangular lattice: sodium rich phases of Na${}_x$CoO${}_2$
• Textured electronic states of the triangular lattice Hubbard model and Na${}_x$CoO${}_2$
• Ground state phase diagram of a spinless, extended Falicov-Kimball model on the triangular lattice
• Considerable non-local electronic correlations in strongly doped Na${}_x$CoO${}_2$
• Spin fluctuations, magnetic long-range order and Fermi surface gapping in NaxCoO2
• Thermodynamic studies of the two dimensional Falicov-Kimball model on a triangular lattice
• Electronic theory for itinerant in-plane magnetic fluctuations in Na${}_x$CoO${}_2$
• Study of ground state phases for spin-1/2 Falicov-Kimball model on a triangular lattice
• Synthesis of sodium cobaltate Na${}_x$CoO${}_2$ single crystals with controlled Na ordering
• Phase transitions in a spinless, extended Falicov-Kimball model on the triangular lattice
• Electron-phonon interaction dressed by electronic correlations near charge ordering as the origin for superconductivity in cobaltates
• Theory of carrier concentration-dependent electronic behavior in layered cobaltates
• New electronic orderings observed in cobaltates under the influence of misfit periodicities
• Orbital Magnetic Field Driven Metal-Insulator Transition in Spinless Extended Falicov-Kimball Model on A Triangular Lattice
• Role of electronic correlations in the Fermi surface formation of Na${}_x$CoO${}_2$
• Metal-Insulator Transition and Band Magnetism in the Spin-$1/2$ Falicov-Kimball Model on A Triangular Lattice with External Magnetic Field
• The Role of Intra- and Inter-site exchange correlations in the Extended Falicov-Kimball Model on a Triangular Lattice
• One-particle spectral properties of the t-J-$V$ model on the triangular lattice near charge order
• Evolution of electron Fermi surface with doping in cobaltates
• Dynamical spin response of electron doped Mott insulators on a triangular lattice
• Similarities in electronic properties of organic charge-transfer solids and layered cobaltates