Normal-State Hourglass Dispersion of the Spin Excitations in FeSe${}_x$Te${}_{1-x}$

Abstract

We use cold neutron spectroscopy to study the low-energy spin excitations of superconducting (SC) FeSe${}_{0.4}$Te${}_{0.6}$ and essentially non-superconducting (NSC) FeSe${}_{0.45}$Te${}_{0.55}$. In contrast to BaFe${}_{2-x}$(Co,Ni)${}_x$As${}_2$, where the low-energy spin excitations are commensurate both in the SC and normal state, the normal-state spin excitations in SC FeSe${}_{0.4}$Te${}_{0.6}$ are incommensurate and show an hourglass dispersion near the resonance energy. Since similar hourglass dispersion is also found in the NSC FeSe${}_{0.45}$Te${}_{0.55}$, we argue that the observed incommensurate spin excitations in FeSe${}_{1-x}$Te${}_x$ are not directly associated with superconductivity. Instead, the results can be understood within a picture of Fermi surface nesting assuming extremely low Fermi velocities and spin-orbital coupling.

4 pages, 4 figures

References in corpus (24)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Density functional study of FeS, FeSe and FeTe: Electronic structure, magnetism, phonons and superconductivity
• Extreme Sensitivity of Superconductivity to Stoichiometry in FeSe (Fe1+dSe)
• Superconductivity close to magnetic instability in Fe(Se1-xTex)0.82
• Incommensurate magnetic order in the alpha-Fe(Te,Se) superconductor systems
• First-order magnetic and structural phase transitions in Fe${}_{1+y}$Se${}_x$Te${}_{1-x}$
• Funtional Renormalization Group Study of the Pairing Symmetry and Pairing Mechanism of the FeAs Based High Temperature Superconductors
• 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
• Theory of magnetic excitations in iron-based layered superconductors
• Two-dimensional resonant magnetic excitation in BaFe1.84Co0.16As2
• Spin Gap and Resonance at the Nesting Wavevector in Superconducting FeSe0.4Te0.6
• Two energy scales in the spin excitations of the high-T_c superconductor La${}_{2-x}$Sr${}_x$CuO${}_4$
• Strong electron correlations in the normal state of FeSe0.42Te0.58
• Neutron scattering as a probe of the Fe-pnicitide superconducting gap
• Three-dimensional Resonance in superconducting BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$
• Evolution of spin excitations into the superconducting state in FeTe1-xSex
• Electronic structure of Fe1.04(Te0.66Se0.34)
• Dispersive Spin Fluctuations in the near optimally-doped superconductor Ba(Fe1-xCox)2As2 ($x$=0.065)
• Incommensurate itinerant antiferromagnetic excitations and spin resonance in the FeTe${}_{0.6}$Se${}_{0.4}$ superconductor
• Linear Response Theory and the Universal Nature of the Magnetic Excitation Spectrum of the Cuprates
• Unusual Relationship between Magnetism and Superconductivity in FeTe${}_{0.5}$Se${}_{0.5}$
• Correlation effects in the iron pnictides
• Coupling of spin and orbital excitations in the iron-based superconductor FeSe(0.5)Te(0.5)

Cited by in corpus (21)

• Antiferromagnetic order and spin dynamics in iron-based superconductors
• Iron based high transition temperature superconductors
• Interplay between magnetism and superconductivity in iron-chalcogenide superconductors: crystal growth and characterizations
• Incommensurate magnetic excitations in superconducting LiFeAs
• Stripes, spin resonance and $d_{x^2-y^2}-$pairing symmetry in FeSe-based layered superconductors
• An unified minimum effective model of magnetism in iron-based superconductors
• Electron doping evolution of the magnetic excitations in BaFe2-xNixAs2
• Structure of spin excitations in heavily electron-doped Li0.8Fe0.2ODFeSe superconductors
• Spin liquid polymorphism in a correlated electron system on the threshold of superconductivity
• Spectral analysis for the iron-based superconductors: Anisotropic spin fluctuations and fully gapped s^{\pm}-wave superconductivity
• Evidence for local moment magnetism in superconducting FeTe0.35Se0.65
• Time-reversal symmetry breaking state near the surface of $s_{\pm }$-superconductor
• Magnetism and superconductivity in Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$
• In-plane magnetic field effect on the neutron spin resonance in optimally doped FeSe${}_{0.4}$Te${}_{0.6}$ and BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$ superconductors
• Thermal evolution of antiferromagnetic correlations and tetrahedral bond angles in superconducting FeTe${}_{1-x}$Se${}_x$
• Magnetic hour-glass dispersion and its relation to high-temperature superconductivity in iron-tuned Fe${}_{1+y}$Te${}_{0.7}$Se${}_{0.3}$
• Common origin of the two types of magnetic fluctuations in iron chalcogenides
• Magnetic glassy phase in FeSeTe single crystals
• Doping dependence of the spin excitations in Fe-based superconductors Fe1+yTe1-xSex
• Temperature dependence of the resonance and low energy spin excitations in superconducting FeTe${}_{0.6}$Se${}_{0.4}$
• Magnetic neutron scattering studies on the Fe-based superconductor system Fe${}_{1+y}$Te${}_{1-x}$Se${}_x$