Neutron spin resonance in a quasi-two-dimensional iron-based superconductor

Abstract

Magnetically mediated Cooper pairing is generally regarded as a key to establish the unified mechanism of unconventional superconductivity. One crucial evidence is the neutron spin resonance arising in the superconducting state, which is commonly interpreted as a spin-exciton from collective particle-hole excitations confined below the superconducting pair-breaking gap ($2\Delta$). Here, on the basis of inelastic neutron scattering measurements on a quasi-two-dimensional iron-based superconductor KCa${}_2$Fe${}_4$As${}_4$F${}_2$, we have discovered a two-dimensional spin resonant mode with downward dispersions, a behavior closely resembling the low branch of the hour-glass-type spin resonance in cuprates. The resonant intensity is predominant by two broad incommensurate peaks near $Q=$(0.5, 0.5) with a sharp energy peak at $E_R=16$ meV. The overall energy dispersion of the mode exceeds the measured maximum total gap ${\Delta }_{\mathrm{tot}}=|{\Delta }_k|+|{\Delta }_{k+Q}|$. These experimental results deeply challenge the conventional understanding of the resonance modes as magnetic excitons regardless of underlining pairing symmetry schemes, and it also points out that when the iron-based superconductivity becomes very quasi-two-dimensional, the electronic behaviors are similar to those in cuprates.

arXiv comment16 pages, 14 figures, including supplementary materials

References in corpus (64)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• A Common Thread: the pairing interaction for the unconventional superconductors
• Gap symmetry and structure of Fe-based superconductors
• Antiferromagnetic order and spin dynamics in iron-based superconductors
• Magnetism, superconductivity, and pairing symmetry in Fe-based superconductors
• Orbital Fluctuation Mediated Superconductivity in Iron Pnictides: Analysis of Five Orbital Hubbard-Holstein Model
• Resonant Spin Excitation in the High Temperature Superconductor Ba0.6K0.4Fe2As2
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• High Temperature Superconductivity in Iron Pnictides and Chalcogenides
• Pairing Symmetry and Pairing State in Ferropnictides: Theoretical Overview
• Pairing Symmetry in a Two-Orbital Exchange Coupling Model of Oxypnictides
• Normal-State Spin Dynamics and Temperature-Dependent Spin Resonance Energy in an Optimally Doped Iron Arsenide Superconductor
• Coexistence of the spin-density-wave and superconductivity in the (Ba,K)Fe2As2
• The effect of collective spin-1 excitations on electronic spectra in high-Tc superconductors
• Theory of magnetic excitations in iron-based layered superconductors
• Spin resonance in the d-wave superconductor CeCoIn5
• From (pi, 0) magnetic order to superconductivity with (pi, pi) magnetic resonance in Fe1.02(Te1-xSex)
• Bilayer Splitting in the Electronic Structure of Heavily Overdoped Bi2Sr2CaCu2O8+d
• Quantum criticality and nodal superconductivity in the FeAs-based superconductor KFe2As2
• Self-Consistent Vertex Correction Analysis for Iron-Based Superconductors: Mechanism of Coulomb-Interaction-Driven Orbital Fluctuations
• Neutron scattering as a probe of the Fe-pnicitide superconducting gap
• Universal relation between magnetic resonance and superconducting gap in unconventional superconductors
• Fe-based superconductors: an angle-resolved photoemission spectroscopy perspective
• Superconductivity in KCa${}_2$Fe${}_4$As${}_4$F${}_2$ with Separate Double Fe${}_2$As${}_2$ Layers
• Structure of Neutron-Scattering Peak in both s++ wave and s+- wave states of an Iron pnictide Superconductor
• Symmetry of spin excitation spectra in the tetragonal paramagnetic and superconducting phases of 122-ferropnictides
• Neutron Scattering Resonance and the Fe-pnictide Superconducting Gap
• Crossover from weak to strong pairing in unconventional superconductors
• Hedgehog spin-vortex crystal stabilized in a hole-doped iron-based superconductor
• Experimental Consequences of the S-wave $\cos (k_x)\cdot \cos (k_y)$ Superconductivity in the Iron-Pnictides
• Synthesis, crystal structure and spin-density-wave anomaly of the iron arsenide-fluoride SrFeAsF
• SrFeAsF as a parent compound for iron pnictide superconductors
• Incommensurate spin fluctuations in hole-overdoped superconductor KFe2As2
• Optimization of the Crystal Growth of the Superconductor CaKFe${}_4$As${}_4$ from Solution in the FeAs-CaFe${}_2$As${}_2$-KFe${}_2$As${}_2$ System
• Electron-doping evolution of the low-energy spin excitations in the iron arsenide BaFe${}_{2-x}$Ni${}_x$As${}_2$ superconductors
• Superconductivity, Antiferromagnetism, and Neutron Scattering
• Superconductivity in Fluorine-Arsenide Sr_{1-x}La_xFeAsF
• Crystal Structure and Superconductivity at about 30 K in $A$Ca${}_2$Fe${}_4$As${}_4$F${}_2$ ($A$ = Rb, Cs)
• Magnetic order in CaFe1-xCoxAsF (x = 0, 0.06, 0.12) superconductor compounds
• Distinguishing $s^{\pm }$ and $s^{++}$ electron pairing symmetries by neutron spin resonance in superconducting NaFe${}_{0.935}$Co${}_{0.045}$As
• Giant anisotropy in superconducting single crystals of CsCa${}_2$Fe${}_4$As${}_4$F${}_2$
• A Mott insulator continuously connected to iron pnictide superconductors
• Single-crystal growth and extremely high H_c2 of 12442-type Fe-based superconductor KCa_2Fe_4As_4F_2
• Synthesis, crystal structure and superconductivity in Rb$L{n}_2$Fe${}_4$As${}_4$O${}_2$ ($Ln$ = Sm, Tb, Dy and Ho)
• Crystal Chemistry and Structural Design of Iron-Based Superconductors
• Nodal multigap superconductivity in KCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Superconductivity at 33 - 37 K in $AL{n}_2$Fe${}_4$As${}_4$O${}_2$ ($A$ = K and Cs; $Ln$ = Lanthanides)
• Odd and even modes of neutron spin resonance in the bilayer iron-based superconductor CaKFe${}_4$As${}_4$
• Robust Upward Dispersion of the Neutron Spin Resonance in the Heavy Fermion Superconductor Ce${}_{1-x}$Yb${}_x$CoIn${}_5$
• Spectroscopic Evidence of Bilayer Splitting and Interlayer Pairing in an Iron Based Superconductor
• Two energy scales in the magnetic resonance spectrum of electron and hole doped pnictide superconductors
• Neutron spin resonance in the 112-type iron-based superconductor
• Antiferromagnetic order in CaK(Fe[1-x]Ni[x])4As4 and its interplay with superconductivity
• Superconductivity at 35 K by self doping in RbGd${}_2$Fe${}_4$As${}_4$O${}_2$
• Strong Pauli paramagnetic effect in the upper critical field of KCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Magnonlike dispersion of spin resonance in Ni-doped BaFe${}_2$As${}_2$
• Low temperature specific heat of 12442-type KCa_2Fe_4As_4F_2 single crystals
• Spin excitations in optimally P-doped BaFe2(As0.7P0.3)2superconductor
• Nature of the spin resonance mode in CeCoIn${}_5$
• Two-dimensional magnetic interactions in LaFeAsO
• Neutron Spin Resonance in the Heavily Hole-doped KFe${}_2$As${}_2$ Superconductor
• Neutron spin resonance as a probe of Fermi surface nesting and superconducting gap symmetry in Ba${}_{0.67}$K${}_{0.33}$(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Observation of a neutron spin resonance in the bilayered superconductor CsCa2Fe4As4F2
• Self-energy driven resonance-like inelastic neutron spectrum in $s_{++}$-wave state in Fe-based superconductors

Cited by in corpus (23)

• Observation of superconducting collective modes from competing pairing instabilities in single-layer NbSe${}_2$
• Friedel Oscillations of Vortex Bound States Under Extreme Quantum Limit in KCa2Fe4As4F2
• Charge Density Wave order and electron-phonon coupling in ternary superconductor Bi${}_2$Rh${}_3$Se${}_2$
• Ultrafast Optical Spectroscopy Evidence of Pseudogap and Electron-Phonon Coupling in an Iron-Based Superconductor KCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Single particle tunneling spectroscopy and superconducting gaps in layered iron based superconductor KCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Anisotropic physical properties and large critical current density in KCa${}_2$Fe${}_4$As${}_4$F${}_2$ single crystal
• Nodal multigap superconductivity in the anisotropic iron-based compound RbCa2Fe4As4F2
• Preferred Spin Excitations in the Bilayer Iron-Based Superconductor CaK(Fe${}_{0.96}$Ni${}_{0.04}$)${}_4$As${}_4$ with Spin-Vortex Crystal Order
• Anomalous second magnetization peak in 12442-type RbCa${}_2$Fe${}_4$As${}_4$F${}_2$ superconductors
• High-energy magnetic excitations from heavy quasiparticles in CeCu${}_2$Si${}_2$
• Pseudogap and Strong Pairing Induced by Incipient and Shallow Bands in the Quasi-Two-Dimensional KCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Spin excitations in the heavily overdoped monolayer graphene superconductor: an analog to the cuprates
• Spectroscopic studies of the superconducting gap in the 12442 family of iron-based compounds
• Second magnetization peak, anomalous field penetration, and Josephson vortices in KCa${}_2$Fe${}_4$As${}_4$F${}_2$ bilayer pnictide superconductor
• Evidence of electron interaction with an unidentified bosonic mode in superconductor CsCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Neutron Spin Resonance Near a Lifshitz Transition in Overdoped Ba${}_{0.4}$K${}_{0.6}$Fe${}_2$As${}_2$
• Anomalous metallic oxygen band in the potential superconductor KCa${}_2$Fe${}_4$As${}_4$O${}_2$
• Common ($\pi$,$\pi$) Band Folding and Surface Reconstruction in FeAs-Based Superconductors
• Low-energy spin excitations in optimally doped CaFe${}_{0.88}$Co${}_{0.12}$AsF superconductor studied with inelastic neutron scattering
• Preformed Cooper Pairs in a Triclinic Iron Pnictide Superconductor
• Spin fluctuations in the 112-type iron-based superconductor Ca${}_{0.82}$La${}_{0.18}$Fe${}_{0.96}$Ni${}_{0.04}$As${}_2$
• Decoupled interband pairing in a bilayer iron-based superconductor evidenced by ultrahigh-resolution ARPES
• Spin Fluctuations in the Rare-Earth Doped Bilayer Nickelates