The Unprecedented Giant Coupling of Fe-spin State and the As-As Hybridization in Iron-Pnictide

Abstract

From first principles calculations we unravel surprisingly strong interactions between arsenic ions in iron-pnictides, the strength of which is controlled by the Fe-spin state. Reducing the Fe-magnetic moment, weakens the Fe-As bonding, and in turn, increases As-As interactions, causing giant reduction in the c-axis. For CaFe${}_2$As${}_2$ system, this reduction is as large as 1.4 Å. Since the large c-reduction has been recently observed only under high-pressure\cite{cTphase}, our results suggest that the iron magnetic moment should be present in Fe-pnictides at all times at ambient pressure. Finally, the conventional electron-phonon coupling in the collapsed phase of CaFe${}_2$As${}_2$ gives a maximum $T_c$ of 0.6 K and can not explain the $\sim 12$ K superconductivity observed in some experiments. Implications of these findings on the mechanism of superconductivity in iron-pnictides are discussed.

Published version with updated references. It has new results such as conventional e-ph coupling in the collapsed phase of CaFe2As2 gives a maximum Tc of 0.6 K and cannot explain the ~12 K superconductivity observed in some experiments. Implications of these findings on the mechanism of superconductivity in iron pnictides are discussed

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Cited by in corpus (54)

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• Possible re-entrant superconductivity in EuFe2As2 under pressure
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• Effects of the magnetic orderings on the dynamical conductivity: optical investigations of EuFe${}_2$As${}_2$ single crystals
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• Spin-state transition in the Fe-pnictides
• Suppression of antiferromagnetic spin fluctuations in the collapsed tetragonal phase of CaFe2As2
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• Successive phase transitions under high pressure in FeTe0.92
• Electronic structure of BaCu${}_2$As${}_2$ and SrCu${}_2$As${}_2$: sp-band metals
• NMR investigation of superconductivity and antiferromagnetism in CaFe${}_2$As${}_2$ under pressure
• Superconductivity without Fe or Ni in the phosphides BaIr2P2 and BaRh2P2
• Anomalous electron-phonon interaction in doped LaOFeAs: a First Principles calculation
• Fermi-Surface Reconstruction and Complex Phase Equilibria in CaFe${}_2$As${}_2$
• Magnetic order in orbital models of the iron pnictides
• Spin-phonon coupling and pressure effect in the superconductor LiFeAs : Lattice dynamics from first-principles calculations
• Structural origin of the anomalous temperature dependence of the local magnetic moments in the CaFe${}_2$As${}_2$ family of materials
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• Pressure Suppression of Electron Correlation in the Collapsed Tetragonal Phase of $CaF{e}_{2}A{s}_2$ : A DFT-DMFT Investigation
• Crystal Symmetry and Magnetic Order in Iron Pnictides: a Tight Binding Wannier Function Analysis
• Tunable Cobalt Vacancies and Related Properties in LaCoxAs2
• Pressure- and temperature-induced structural phase transitions of CaFe${}_2$As${}_2$ and BaFe${}_2$As${}_2$ studied in the Hund's rule correlation picture
• Spin dependent electron-phonon interaction in SmFeAsO by low-temperature Raman spectroscopy
• Direct spectroscopic evidence for completely filled Cu $3d$ shell in BaCu${}_2$As${}_2$ and $\alpha$-BaCu${}_2$Sb${}_2$
• Theoretical investigation of FeTe magnetic ordering under hydrostatic pressure
• Phase diagram of Josephson junction between s and s+- superconductors in dirty limit
• First-principles study of superconducting Rare-earth doped CaFe2As2
• Origin of doping-induced suppression and reemergence of magnetism in LaFeAsO${}_{1-x}$H${}_x$
• Quenched Fe Moment in the Collapsed Tetragonal Phase of Ca${}_{1-x}$Pr${}_x$Fe${}_2$As${}_2$
• Structural, electronic, and dynamical properties of the tetragonal and collapsed tetragonal phases of KFe${}_2$As${}_2$
• Suppression of magnetic order in CaCo${}_{1.86}$As${}_2$ with Fe substitution: Magnetization, neutron diffraction, and x-ray diffraction studies of Ca(Co${}_{1-x}$Fe${}_x$)${}_y$As${}_2$
• Optical properties of the iron-chalcogenide superconductor FeTe0.55Se0.45
• Combined effects of transition metal (Ni and Rh) substitution and annealing/quenching on physical properties of CaFe${}_2$As${}_2$
• Formation of As-As Bond and Its Effect on Absence of Superconductivity in Collapsed Tetragonal Phase of Ca0.86Pr0.14Fe2As2 : An Optical Spectroscopy Study
• Role of electron-electron interactions in the charge dynamics of rare-earth-doped CaFe2As2
• Influence of the surface symmetry breaking on the magnetism, collapsing and three dimensional dispersion of Co pnictides ACo2As2 (A=Ba, Sr, Ca)
• The high-pressure phase diagram of BaNi${}_2$As${}_2$: unconventional charge-density-waves and structural phase transitions
• Correlation effects in Ni 3d states of LaNiPO
• Drastic electronic structure reconstruction of Ca${}_{1-x}$Pr${}_x$Fe${}_2$As${}_2$ in the collapsed tetragonal phase
• Optical spectroscopy study of the collapsed tetragonal phase of CaFe${}_2$(As${}_{0.935}$P${}_{0.065}$)${}_2$ single crystals
• Anomalous local magnetic field distribution and strong pinning in CaFe1.94Co0.06As2 single crystals
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• Breakdown of the Hund's Rule in CuFeAs
• Elasto-Raman scattering: arsenic optical phonon as a probe of nematicity in BaFe${}_2$As${}_2$
• Electronic band structures and intra-atomic interactions in layered quaternary oxyarsenides LaZnAsO and YZnAsO