Ising-nematic order in the bilinear-biquadratic model for the iron pnictides

Abstract

Motivated by the recent inelastic neutron scattering (INS) measurements in the iron pnictides which show a strong anisotropy of spin excitations in directions perpendicular and parallel to the ordering wave-vector even above the magnetic transition temperature $T_N$, we study the frustrated Heisenberg model with a biquadratic spin-spin exchange interaction. Using the Dyson-Maleev (DM) representation, which proves appropriate for all temperature regimes, we find that the spin-spin dynamical structure factors are in excellent agreement with experiment, exhibiting breaking of the $C_4$ symmetry even into the paramagnetic region $T_N<T<T_{\sigma }$ which we refer to as the Ising-nematic phase. In addition to the Heisenberg spin interaction, we include the biquadratic coupling $K({\mathbf{S}}_i\cdot {\mathbf{S}}_j{)}^2$ and study its effect on the dynamical temperature range $T_{\sigma }-T_N$ of the Ising-nematic phase. We find that this range reduces dramatically when even small values of the interlayer exchange $J_c$ and biquadratic coupling $K$ are included. To supplement our analysis, we benchmark the results obtained using the DM method against those from different non-linear spin-wave theories, including the recently developed generalized spin-wave theory (GSWT), and find good qualitative agreement among the different theoretical approaches as well as experiment for both the spin-wave dispersions and the dynamical structure factors.

References in corpus (33)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Nematic order in iron superconductors - who is in the driver's seat?
• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
• Theory of Electron Nematic Order in LaOFeAs
• Origin of the ~150 K Anomaly in LaOFeAs; Competing Antiferromagnetic Superexchange Interactions, Frustration, and Structural Phase Transition
• Correlated electronic structure of LaOFeAs
• The Structural Phase Transition in FeSe (Fe1+dSe)
• Coherence-incoherence crossover in the normal state of iron-oxypnictides and importance of the Hund's rule coupling
• Ising and Spin orders in Iron-based Superconductors
• Fe-based high temperature superconductivity with Tc=31K bordering an insulating antiferromagnet in (Tl,K)FexSe2 Crystals
• Orbital-driven nematicity in FeSe
• Spin-orbital frustrations and anomalous metallic state in iron-pnictide superconductors
• Origin of the spin density wave instability in AFe${}_2$As${}_2$ (A=Ba, Sr) as revealed by optical spectroscopy
• Nodal Spin Density Wave and band topology of the FeAs based materials
• Origin of the tetragonal-to-orthorhombic (nematic) phase transition in FeSe: a combined thermodynamic and NMR study
• Antiferromagnetic superexchange interactions in LaOFeAs
• Lifting of xz/yz orbital degeneracy at the structural transition in detwinned FeSe
• Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in A${}_x$Fe${}_{2-y}$Se${}_2$ (A=K, Rb) Superconductors
• Orbital Order and Spontaneous Orthorhombicity in Iron Pnictides
• Nematic spin correlations in the tetragonal state of uniaxial strained BaFe2-xNixAs2
• Orbital-selective Mott Phase in Multiorbital Models for Alkaline Iron Selenides K(1-x)Fe(2-y)Se2
• Low energy spin waves and magnetic interactions in SrFe${}_2$As${}_2$
• Manifestations of nematic degrees of freedom in the magnetic, elastic, and superconducting properties of the iron pnictides
• Nature of magnetic excitations in superconducting BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$
• Anisotropy, Itineracy, and Magnetic Frustration in High-Tc Iron Pnictides
• Theory of itinerant magnetic excitations in the SDW phase of iron-based superconductors
• Itinerant Spin Excitations in SrFe2As2 Measured by Inelastic Neutron Scattering
• Correlation effects in the iron pnictides
• Pnictides as frustrated quantum antiferromagnet close to a quantum phase transition
• Signatures of Electronic Correlations in Optical Properties of LaFeAsO${}_{1-x}$F${}_x$
• Weak spin interactions in Mott insulating La2O2Fe2OSe2
• Orbital Nematic Order and Interplay with Magnetism in the Two-Orbital Hubbard Model

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• Spin Ferroquadrupolar Order in the Nematic Phase of FeSe
• Possible Nematic Spin Liquid in Spin-$1$ Antiferromagnetic System on the Square Lattice: Implication for the Nematic Paramagnetic State of FeSe
• Spin and quadrupolar orders in the spin-1 bilinear-biquadratic model for iron-based superconductors
• Magnetic and Structural Properties of the Iron Oxychalcogenides La${}_2$O${}_2$Fe${}_2$O$M_2$ ($M$= S, Se)
• Spin-$S$ designer hamiltonians and the square lattice $S=1$ Haldane nematic
• Quantum phase transition between spin liquid and spin nematics in spin-1 Kitaev honeycomb model
• Anisotropic magnetic excitations of a frustrated bilinear-biquadratic spin model -- Implications for spin waves of detwinned iron pnictides
• Superconducting states of a J1-J2-K model for iron pnictides
• Unified Spin Model for Magnetic Excitations in Iron Chalcogenides