Observation of Two Cascading Screening Processes in an Iron-based Superconductor

Abstract

Understanding how renormalized quasiparticles emerge in strongly correlated electron materials provides a challenge for both experiment and theory. It has been predicted that distinctive spin and orbital screening mechanisms drive this process in multiorbital materials with strong Coulomb and Hund's interactions. Here, we provide the experimental evidence of both mechanisms from angle-resolved photoemission spectroscopy on RbFe${}_2$As${}_2$. We observe that the emergence of low-energy Fe 3$d_{xy}$ quasiparticles below 90K is tied to spin screening. A second process changes the spectral weight at high energies up to room temperature. Supported by theoretical calculations we attribute it to orbital screening of Fe 3d atomic excitations. These two cascading screening processes drive the temperature evolution from a bad metal to a correlated Fermi liquid.

References in corpus (49)

• A continuous-time solver for quantum impurity models
• Strong electronic correlations from Hund's coupling
• Kinetic frustration and the nature of the magnetic and paramagnetic states in iron pnictides and iron chalcogenides
• Antiferromagnetic order and spin dynamics in iron-based superconductors
• The ALPS project release 2.0: Open source software for strongly correlated systems
• Determination of the phase diagram of the electron doped superconductor Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• 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
• Electronic correlations in the iron pnictides
• Selective Mottness as a key to iron superconductors
• Janus-faced influence of the Hund's rule coupling in strongly correlated materials
• The Unexpected Properties of Alkali Metal Iron Selenide Superconductors
• Exact double-counting in combining the Dynamical Mean Field Theory and the Density Functional Theory
• Hund's coupling key role in multi-orbital correlations
• Observation of universal strong orbital-dependent correlation effects in iron chalcogenides
• Spectroscopic scanning tunneling microscopy insights into Fe-based superconductors
• Evidence of Strong Correlations and Coherence-Incoherence Crossover in the Iron Pnictide Superconductor KFe2As2
• Recent progress on correlated electron systems with strong spin-orbit coupling
• Magnetoresistance near a quantum critical point
• Driven Markovian Quantum Criticality
• Formation of Hubbard-like bands as a fingerprint of strong electron-electron interactions in FeSe
• Covalency in transition metal oxides within all-electron Dynamical Mean Field Theory
• Identifying the maximum entropy method as a special limit of stochastic analytic continuation
• Hundness versus Mottness in a three-band Hubbard-Hund model: On the origin of strong correlations in Hund metals
• Observation of a novel orbital selective Mott transition in Ca${}_{1.8}$Sr${}_{0.2}$RuO${}_4$
• Emergent Kondo scaling in iron-based superconductors AFe2As2 (A = K, Rb, Cs)
• Signatures of Mottness and Hundness in archetypal correlated metals
• Non-Thermal Emergence of an Orbital-Selective Mott Phase in FeTe${}_{1-x}$Se${}_x$
• Correlation-Driven Electronic Reconstruction in FeTe${}_{1-x}$Se${}_x$
• Microscopic nature of correlations in multi-orbital AFe2As2 (A=K, Rb, Cs): Hund's coupling versus Coulomb repulsion
• Orbital differentiation in Hund metals
• Detailed band structure of twinned and detwinned BaFe${}_2$As${}_2$ studied with angle-resolved photoemission spectroscopy
• Correlation effects in the tetragonal and collapsed tetragonal phase of CaFe2As2
• Heat transport in RbFe2As2 single crystal: evidence for nodal superconducting gap
• Hubbard interactions in iron-based pnictides and chalcogenides: Slater parametrization, screening channels and frequency dependence
• The Hund-metal path to strong electronic correlations
• Direct observation of dispersive lower Hubbard band in iron-based superconductor FeSe
• Universal Knight shift anomaly in the Periodic Anderson model
• Differentiating Hund from Mott physics in a three-band Hubbard-Hund model: Temperature dependence of spectral, transport, and thermodynamic properties
• Emerging symmetric strain response and weakening nematic fluctuations in strongly hole-doped iron-based superconductors
• Temperature-induced band selective localization and coherent-incoherent crossover in single-layer FeSe/Nb:BaTiO3 /KTaO3
• The fate of quasiparticles at high-temperature
• Hund's metal crossover and superconductivity in the 111 family of iron-based superconductors
• Updated Core Libraries of the ALPS Project
• Electronic excitation spectra of the five-orbital Anderson impurity model: From the atomic limit to itinerant atomic magnetism
• In-gap band in the one-dimensional two-orbital Kanamori-Hubbard model with inter-orbital Coulomb interaction
• Low work function in the 122-family of iron-based superconductors
• Hund bands in spectra of multiorbital systems
• Van Hove singularities, chemical pressure and phonons: an angle-resolved photoemission study of KFe${}_2$As${}_2$ and CsFe${}_2$As${}_2$

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