Strength of correlations in pnictides and its assessment by theoretical calculations and spectroscopy experiments

Abstract

LDA+DMFT (Local Density Approximation combined with Dynamical Mean-Field Theory) computation scheme has been used to calculate spectral properties of LaFeAsO -- the parent compound of the new high-T_c iron oxypnictides. The average Coulomb repulsion U=3-4 eV and Hund's exchange J=0.8 eV parameters for iron 3d electrons were calculated using the first principles constrained density functional theory scheme in the Wannier functions formalism. DMFT calculations using these parameters result in moderately correlated electronic structure with effective electron mass enhancement m^*~2 that is in agreement with the experimental X-ray and photoemission spectra. Conclusion of moderate correlations strength is confirmed by the observation that pnictides experimental spectra agree well with corresponding spectra for metallic iron while being very different with Mott insulator FeO spectra.

References in corpus (16)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Calculations of Hubbard U from first-principles
• Correlated electronic structure of LaOFeAs
• Electronic structure of the iron-based superconductor LaOFeP
• Screened Coulomb interaction in the maximally localized Wannier basis
• Fermi surface of superconducting LaFePO determined by quantum oscillations
• Ab initio Derivation of Low-energy Model for Iron-Based Superconductors LaFeAsO and LaFePO
• Construction and solution of a Wannier-functions based Hamiltonian in the pseudopotential plane-wave framework for strongly correlated materials
• Electronic Structure and Electron Correlation in LaFeAsO_{1-x}F_x and LaFePO_{1-x}F_x
• Normal State Correlated Electronic Structure of Iron Pnictides
• Electromagnetic properties and electronic structure of iron-based layered superconductor LaOFeP
• On the electronic structure of electron doped LaOFeAs as seen by X-ray absorption spectroscopy
• X-ray spectra and electronic structure of FeAs superconductors
• Electronic Structure of Superconducting FeSe Studied by High-Resolution Photoemission Spectroscopy
• Valence band and core level photoemission spectros-copy of LaFeAsO${}_{1-x}$F${}_x$
• Non-Fermi-liquid phases in the two-band Hubbard model: Finite-temperature exact diagonalization study of Hund's rule coupling

Cited by in corpus (12)

• Orbital Order and Spontaneous Orthorhombicity in Iron Pnictides
• Unconventional electronic reconstruction in undoped (Ba,Sr)Fe${}_2$As${}_2$ across the spin density wave transition
• Electronic Structure Calculation by First Principles for Strongly Correlated Electron Systems
• Dichotomy between large local and small ordered magnetic moment in Iron-based superconductors
• Classification of the electronic correlation strength in the Fe-pnictides: The case of the parent compound BaFe2As2
• Effect of 3d-doping on the electronic structure of BaFe2As2
• The magnetic moment enigma in Fe-based high temperature superconductors
• Electronic Structure of CeFeAsO1-xFx (x=0, 0.11/x=0.12) compounds
• Magnetic Properties of Ab initio Model for Iron-Based Superconductors LaFeAsO
• Orbital Symmetry of Ba(Fe1-xCox)2As2 Superconductors Probed with X-ray Absorption Spectroscopy
• The electronic structure of Co-substituted $\text{Fe}\text{Se}$ superconductor probed by soft X-ray spectroscopy and density functional theory
• A direct probe of the variability of Coulomb correlation in Fe-pnictide superconductors