Mott-Kondo Insulator Behavior in the Iron Oxychalcogenides

Abstract

We perform a combined experimental-theoretical study of the Fe-oxychalcogenides (FeO$\text{Ch}$) series La${}_2$O${}_2$Fe${}_2$O\emph{M}${}_2$ (\emph{M}=S, Se), which is the latest among the Fe-based materials with the potential \ to show unconventional high-T${}_c$ superconductivity (HTSC). A combination of incoherent Hubbard features in X-ray absorption (XAS) and resonant inelastic X-ray scattering (RIXS) spectra, as well as resitivity data, reveal that the parent FeO$\text{Ch}$ are correlation-driven insulators. To uncover microscopics underlying these findings, we perform local density approximation-plus-dynamical mean field theory (LDA+DMFT) calculations that unravel a Mott-Kondo insulating state. Based upon good agreement between theory and a range of data, we propose that FeO$\text{Ch}$ may constitute a new, ideal testing ground to explore HTSC arising from a strange metal proximate to a novel selective-Mott quantum criticality.

References in corpus (12)

• Magnetism, superconductivity, and pairing symmetry in Fe-based superconductors
• Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
• Hidden Magnetism and Quantum Criticality in the Heavy Fermion Superconductor CeRhIn5
• Coherence-incoherence crossover in the normal state of iron-oxypnictides and importance of the Hund's rule coupling
• Fe-based high temperature superconductivity with Tc=31K bordering an insulating antiferromagnet in (Tl,K)FexSe2 Crystals
• Why Does Undoped FeSe Become A High Tc Superconductor Under Pressure?
• Low-temperature nuclear and magnetic structures of La2O2Se2.Fe2O from X-ray and neutron diffraction measurements
• X-ray spectra and electronic structure of FeAs superconductors
• Weak spin interactions in Mott insulating La2O2Fe2OSe2
• Strength of correlations in pnictides and its assessment by theoretical calculations and spectroscopy experiments
• Multi-orbital Effects in Optical Properties of Vanadium Sesquioxide
• La${}_2$O${}_3$Fe${}_2$Se${}_2$, a Mott insulator on the brink of orbital-selective metalization

Cited by in corpus (9)

• High Temperature Superconductivity in Iron Pnictides and Chalcogenides
• The magnetic and electronic properties of Oxyselenides - influence of transition metal ions and lanthanides
• Pressure-induced transition from a Mott insulator to a ferromagnetic Weyl metal in La2O3Fe2Se2
• Magnetic and Structural Properties of the Iron Oxychalcogenides La${}_2$O${}_2$Fe${}_2$O$M_2$ ($M$= S, Se)
• Magnetic order and phase transition in the iron oxysulfide La2O2Fe2OS2
• Microscopic description of insulator-metal transition in high-pressure oxygen
• Magnetic surface reconstruction in the van-der-Waals antiferromagnet Fe${}_{1+x}$Te
• Anisotropic magnetic excitations of a frustrated bilinear-biquadratic spin model -- Implications for spin waves of detwinned iron pnictides
• Strong charge and spin fluctuations in La${}_2$O${}_3$Fe${}_2$Se${}_2$