High-energy pseudogap in degenerate Hubbard model induced via Hund coupling

Abstract

Hund coupling in the degenerate five-band Hubbard model near n=6 occupancy is shown to give rise to a significant depletion of spectral weight above the Fermi level. Calculations within dynamical mean field theory combined with exact diagonalization reveal that this pseudogap is associated with a collective mode in the self-energy caused by spin fluctuations. The pseudogap is remarkably stable over a wide range of Coulomb and exchange energies, but disappears for weak Hund coupling. The implications of this phenomenon for optical spectra of iron pnictides are discussed.

4 pages, 4 figures

References in corpus (17)

• Correlated electronic structure of LaOFeAs
• Coherence-incoherence crossover in the normal state of iron-oxypnictides and importance of the Hund's rule coupling
• Dynamical Mean-Field Theory within an Augmented Plane-Wave Framework: Assessing Electronic Correlations in the Iron Pnictide LaFeAsO
• Magnetism and Charge Dynamics in Iron Pnictides
• Origin of the spin density wave instability in AFe${}_2$As${}_2$ (A=Ba, Sr) as revealed by optical spectroscopy
• Spin freezing transition and non-Fermi-liquid self-energy in a 3-orbital model
• Theoretical evidence for strong correlations and incoherent metallic state in FeSe
• Hund's coupling key role in multi-orbital correlations
• Kinks in the dispersion of strongly correlated electrons
• Dichotomy between large local and small ordered magnetic moment in Iron-based superconductors
• Metal-Insulator phase diagram and orbital selectivity in 3-orbital models with rotationally invariant Hund coupling
• Classification of the electronic correlation strength in the Fe-pnictides: The case of the parent compound BaFe2As2
• Neutron and ARPES Constraints on the Couplings of the Multiorbital Hubbard Model for the Pnictides
• Normal State Correlated Electronic Structure of Iron Pnictides
• Doping dependence of spin fluctuations and electron correlations in iron pnictides
• Strength of correlations in pnictides and its assessment by theoretical calculations and spectroscopy experiments
• Emergent Collective Modes and Kinks in Electronic Dispersions

Cited by in corpus (17)

• Strong electronic correlations from Hund's coupling
• Fractional power-law behavior and its origin in iron-chalcogenide and ruthenate superconductors: Insights from first-principles calculations
• Temperature and bath size in exact diagonalization dynamical mean field theory
• Magnetic interactions in iron superconductors: A review
• Exotic magnetic order in the orbital-selective Mott regime of multiorbital systems
• Microscopic nature of correlations in multi-orbital AFe2As2 (A=K, Rb, Cs): Hund's coupling versus Coulomb repulsion
• Evolution from unconventional spin density wave to superconductivity and a novel gap-like phase in NaFe1-xCoxAs
• Distributional exact diagonalization formalism for quantum impurity models
• Nature of the bad metallic behavior of Fe_{1.06}Te inferred from its evolution in the magnetic state
• Insulator-to-metal transition and large thermoelectric effect in La${}_{1-x}$Sr${}_x$MnAsO
• Quantum phase transition between orbital-selective Mott states in Hund's metals
• Ab-initio perspective on structural and electronic properties of iron-based superconductors
• Smooth self-energy in the exact-diagonalization-based dynamical mean-field theory: Intermediate-representation filtering approach
• Investigation of correlation effects in FeSe and FeTe by LDA + U method
• Development of an efficient impurity solver in dynamical mean field theory for multi-band systems: The iterative perturbation theory combined with the parquet equations
• A Standard Basis Operator Equation of Motion Impurity Solver for Dynamical Mean Field Theory
• Hund's metallicity enhanced by van Hove singularity in cubic perovskite systems