Orbital-selective spin waves in detwinned NaFeAs

Abstract

The existence of orbital-dependent electronic correlations has been recognized as an essential ingredient to describe the physics of iron-based superconductors. NaFeAs, a parent compound of iron based superconductors, exhibits a tetragonal-to-orthorhombic lattice distortion below $T_s\approx 60$ K, forming an electronic nematic phase with two 90${}^{\circ }$ rotated (twinned) domains, and orders antiferromagnetically below $T_N\approx 42$ K. We use inelastic neutron scattering to study spin waves in uniaxial pressure-detwinned NaFeAs. By comparing the data with combined density functional theory and dynamical mean-field theory calculations, we conclude that spin waves up to an energy scale of $E_{\text{crossover}}\approx 100$ meV are dominated by $d_{yz}$-$d_{yz}$ intra-orbital scattering processes, which have the two-fold ($C_2$) rotational symmetry of the underlying lattice. On the other hand, the spin wave excitations above $E_{\text{crossover}}$, which have approximately fourfold ($C_4$) rotational symmetry, arise from the $d_{xy}$-$d_{xy}$ intra-orbital scattering that controls the overall magnetic bandwidth in this material. In addition, we find that the low-energy ($E\approx 6$ meV) spin excitations change from approximate $C_4$ to $C_2$ rotational symmetry below a temperature $T^{\ast }$ ($>T_s$), while spin excitations at energies above $E_{\text{crossover}}$ have approximate $C_4$ rotational symmetry and are weakly temperature dependent. These results are consistent with angle resolved photoemission spectroscopy measurements, where the presence of an uniaxial strain necessary to detwin NaFeAs also raises the onset temperature $T^{\ast }$ of observable orbital-dependent band splitting to above $T_s$, thus supporting the notion of orbital selective spin waves in the nematic phase of iron-based superconductors.

12 pages, 7 figures

References in corpus (19)

• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• Evidence for an electron nematic phase transition in underdoped iron pnictide superconductors
• Magnetic order in BaFe2As2, the parent compound of the FeAs based superconductors in a new structural family
• Quantum Monte Carlo Impurity Solver for Cluster DMFT and Electronic Structure Calculations in Adjustable Base
• The Structural Phase Transition in FeSe (Fe1+dSe)
• Structure, antiferromagnetism and superconductivity of the layered iron arsenide NaFeAs
• Nematicity, magnetism and superconductivity in FeSe
• Nematic spin correlations in the tetragonal state of uniaxial strained BaFe2-xNixAs2
• Neutron scattering as a probe of the Fe-pnicitide superconducting gap
• Fractional power-law behavior and its origin in iron-chalcogenide and ruthenate superconductors: Insights from first-principles calculations
• Itinerant Spin Excitations in SrFe2As2 Measured by Inelastic Neutron Scattering
• Anisotropic spin fluctuations in detwinned FeSe
• Orbital-differentiated coherence-incoherence crossover identified by photoemission spectroscopy in LiFeAs
• Spectral analysis for the iron-based superconductors: Anisotropic spin fluctuations and fully gapped s^{\pm}-wave superconductivity
• Uniaxial pressure effect on the magnetic ordered moment and transition temperatures in BaFe${}_{2-x}{T}_x$As${}_2$ ($T=$Co, Ni)
• The evolution of antiferromagnetic susceptibility to uniaxial pressure in Ba(Fe{1-x}Co{x})2As2
• Spin fluctuation anisotropy as a probe of orbital-selective hole-electron quasiparticle excitations in detwinned Ba(Fe1-xCox)2As2
• Orbital selective neutron spin resonance in underdoped superconducting NaFe${}_{\text{0.985}}$Co${}_{\text{0.015}}$As
• Impact of the first order antiferromagnetic phase transition on the paramagnetic spin excitations and nematic phase of SrFe${}_2$As${}_2$

Cited by in corpus (1)

• Spin dynamics in NaFeAs and NaFe${}_{0.53}$Cu${}_{0.47}$As probed by resonant inelastic X-ray scattering