Spin excitation anisotropy in the paramagnetic tetragonal phase of BaFe2 As2

Abstract

We use neutron polarization analysis to study temperature dependence of the spin excitation anisotropy in BaFe${}_2$As${}_2$, which has a tetragonal-to-orthorhombic structural distortion at $T_s$ and antiferromagnetic (AF) phase transition at $T_N$ with ordered moments along the orthorhombic $a$-axis below $T_s\approx T_N\approx 136$ K. In the paramagnetic tetragonal state at 160 K, spin excitations are isotropic in spin space with $M_a=M_b=M_c$, where $M_a$, $M_b$, and $M_c$ are spin excitations polarized along the $a$, $b$, and $c$-axis directions of the orthorhombic lattice, respectively. On cooling towards $T_N$, significant spin excitation anisotropy with $M_a>M_b\approx M_c$ develops below 3 meV with a diverging $M_a$ at $T_N$. The in-plane spin excitation anisotropy in the tetragonal phase of BaFe${}_2$As${}_2$ is similar to those seen in the tetragonal phase of its electron and hole-doped superconductors, suggesting that spin excitation anisotropy is a direct probe of doping dependence of spin-orbit coupling and its connection to superconductivity in iron pnictides.

arXiv comment6 pages,4 figures, in press with PRB rapid

References in corpus (36)

• Superconductivity in Iron Compounds
• Nematic order in iron superconductors - who is in the driver's seat?
• Magnetic order in BaFe2As2, the parent compound of the FeAs based superconductors in a new structural family
• Antiferromagnetic order and spin dynamics in iron-based superconductors
• Iron-Based Superconductors: current status of materials and pairing mechanism
• Ferro-Orbital Order and Strong Magnetic Anisotropy in the Parent Compounds of Iron-Pnictide Superconductors
• Preemptive nematic order, pseudogap, and orbital order in the iron pnictides
• Spin-orbital frustrations and anomalous metallic state in iron-pnictide superconductors
• Ubiquitous signatures of nematic quantum criticality in optimally doped Fe-based superconductors
• Orbital-Ordering Induces Structural Phase Transition and the Resistivity Anomaly in Iron Pnictides
• Structure, antiferromagnetism and superconductivity of the layered iron arsenide NaFeAs
• In-plane electronic anisotropy of underdoped "122" Fe-arsenide superconductors revealed by measurements of detwinned single crystals
• Orbital Order and Spontaneous Orthorhombicity in Iron Pnictides
• Phase Diagram of Ba1-xKxFe2As2
• Magnetically-Driven Suppression of Nematic Order in an Iron-Based Superconductor
• Space group symmetry, spin-orbit coupling and the low energy effective Hamiltonian for iron based superconductors
• Character of the structural and magnetic phase transitions in the parent and electron doped BaFe2As2 compounds
• Double-Q spin-density wave in iron arsenide superconductors
• Electronic nematic susceptibility of iron-based superconductors
• The nature of the magnetic and structural phase transitions in BaFe${}_2$As${}_2$
• Conductivity anisotropy in the antiferromagnetic state of iron pnictides
• Spin reorientation in Na-doped BaFe${}_2$As${}_2$ studied by neutron diffraction
• Distinguishing spin-orbit coupling and nematic order in the electronic spectrum of iron-based superconductors
• Spin excitation anisotropy as a probe of orbital ordering in the paramagnetic tetragonal phase of superconducting BaFe1.904Ni0.096As2
• Splitting of resonance excitations in nearly optimally doped Ba(Fe0.94Co0.06)2As2: an inelastic neutron scattering study with polarization analysis
• Anisotropic Neutron Spin Resonance in Superconducting BaFe${}_{1.9}$Ni${}_{0.1}$As${}_2$
• Local magnetic anisotropy in BaFe${}_2$As${}_2$: a polarized inelastic neutron scattering study
• In-plane spin excitation anisotropy in the paramagnetic phase of NaFeAs
• Nematic crossover in BaFe${}_2$As${}_2$ under uniaxial stress
• Electronic nematic correlations in the stress free tetragonal state of BaFe${}_{2-x}$Ni${}_x$As${}_2$
• Magnetic anisotropy in hole-doped superconducting Ba 0.67K 0.33Fe 2As2 probed by polarized inelastic neutron scattering
• Anisotropic neutron spin resonance in underdoped superconducting NaFe1-xCoxAs
• Anisotropy of incommensurate magnetic excitations in slightly overdoped Ba${}_{0.5}$K${}_{0.5}$Fe${}_2$As${}_2$ probed by polarized inelastic neutron scattering experiments
• Spin anisotropy due to spin-orbit coupling in optimally hole-doped Ba${}_{0.67}$K${}_{0.33}$Fe${}_2$As${}_2$
• Antiferromagnetic Critical Fluctuations in BaFe${}_2$As${}_2$
• Magnetic neutron diffraction study of Ba(Fe1-xCox)2As2 critical exponents through the tricritical doping

Cited by in corpus (9)

• Uniaxial strain control of spin-polarization in multicomponent nematic order of BaFe${}_2$As${}_2$
• Coexistence of ferromagnetic and stripe antiferromagnetic spin fluctuations in SrCo${}_2$As${}_2$
• Spin Waves in Detwinned BaFe${}_2$As${}_2$
• Spin-Orbit Coupling and Magnetic Anisotropy in Iron-Based Superconductors
• In-plane uniaxial pressure-induced out-of-plane antiferromagnetic moment and critical fluctuations in BaFe${}_2$As${}_2$
• Spin excitation anisotropy in optimal-isovalent-doped superconductor BaFe2(As0.7P0.3)2
• Temperature and polarization dependence of low-energy magnetic fluctuations in nearly-optimal-doped NaFe${}_{0.9785}$Co${}_{0.0215}$As
• Longitudinal modes of spin fluctuations in iron-based superconductors
• Polarized neutron scattering studies of magnetic excitations in iron-selenide superconductor (Li${}_{0.8}$Fe${}_{0.2}$)ODFeSe ($T_c$ = 41 K)