Interplay of charge and spin fluctuations in a Hund's coupled impurity

Abstract

In Hund's metals, the local ferromagnetic interaction between orbitals leads to an emergence of complex electronic states with large and slowly fluctuating magnetic moments. Introducing the Hund's coupled mixed valence quantum impurity, we gain analytic insight into recent numerical renormalization group studies. We show that valence fluctuations drastically impede the development of a large fluctuating moment over a wide range of temperatures and energy, characterized by quenched orbital degrees of freedom and a singular logarithmic behavior of the spin susceptibility ${\chi }_{\mathrm{sp}}^{\prime \prime }(\omega )\propto [\omega \ln (\omega /T_K^{\mathrm{eff}}{)}^2{]}^{-1}$, closely resembling power-law scaling ${\chi }_{\mathrm{sp}}^{\prime \prime }(\omega )\sim {\omega }^{-\gamma }$. Such singular spin fluctuations are suspected to play an important role in future models of Hund's driven Cooper pairing.

7 pages, 4 figures (plus supplementary materials: 13 pages, 4 figures)

References in corpus (18)

• Strong electronic correlations from Hund's coupling
• Coherence-incoherence crossover in the normal state of iron-oxypnictides and importance of the Hund's rule coupling
• Spin freezing transition and non-Fermi-liquid self-energy in a 3-orbital model
• Hund's coupling key role in multi-orbital correlations
• Fractional power-law behavior and its origin in iron-chalcogenide and ruthenate superconductors: Insights from first-principles calculations
• Dichotomy between large local and small ordered magnetic moment in Iron-based superconductors
• Electronic correlations, magnetism and Hund's rule coupling in the ruthenium perovskites SrRuO${}_3$ and CaRuO${}_3$
• Metal-Insulator phase diagram and orbital selectivity in 3-orbital models with rotationally invariant Hund coupling
• Kondo resonance narrowing in d- and f-electron systems
• Strong Correlations, Strong Coupling and s-wave Superconductivity in Hole-doped BaFe2As2 Single Crystals
• Hund interaction, spin-orbit coupling and the mechanism of superconductivity in strongly hole-doped iron pnictides
• Sum Rules and Ward Identities in the Kondo Lattice
• Schwinger Boson approach to the fully screened Kondo model
• Is the orbital-selective Mott phase stable against interorbital hopping?
• Emergent Spinon Dispersion and Symmetry Breaking in Two-Channel Kondo Lattices
• Emergent moments in a Hund's impurity
• Observation of an Emergent Coherent State in the Iron-Based Superconductor KFe${}_2$As${}_2$
• Schwinger boson approach for the dynamical mean-field theory of the Kondo lattice

Cited by in corpus (5)

• Heavy-fermions in frustrated Hund's metal with portions of incipient flat-bands
• Frozen spin ratio and the detection of Hund correlations
• Dynamic-RKKY induced time-reversal symmetry breaking and chiral spin liquids
• Towards Entanglement Entropy of Random Large-N Theories
• Triplet pairing, orbital selectivity and correlations in Iron-based superconductors