Multi-orbital quantum antiferromagnetism in iron pnictides --- effective spin couplings and quantum corrections to sublattice magnetization

Abstract

Towards understanding the multi-orbital quantum antiferromagnetism in iron pnictides, effective spin couplings and spin fluctuation induced quantum corrections to sublattice magnetization are obtained in the $(\pi ,0)$ AF state of a realistic three band interacting electron model involving $xz$, $yz$, and $xy$ Fe 3d orbitals. The $xy$ orbital is found to be mainly responsible for the generation of strong ferromagnetic spin coupling in the $b$ direction, which is critically important to fully account for the spin wave dispersion as measured in inelastic neutron scattering experiments. The ferromagnetic spin coupling is strongly suppressed as the $xy$ band approaches half filling, and is ascribed to particle-hole exchange in the partially filled $xy$ band. The strongest AF spin coupling in the $a$ direction is found to be in the orbital off diagonal sector involving the $xz$ and $xy$ orbitals. First order quantum corrections to sublattice magnetization are evaluated for the three orbitals, and yield a significant $37\%$ average reduction from the Hartree-Fock value.

17 pages, 4 figures

References in corpus (21)

• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Evidence for an electron nematic phase transition in underdoped iron pnictide superconductors
• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Structural and magnetic phase diagram of CeFeAsO1-xFx and its relationship to high-temperature superconductivity
• Correlated electronic structure of LaOFeAs
• Nematic and meta-nematic transitions in the iron pnictides
• Magnetism in Fe-based superconductors
• Magnetism and Charge Dynamics in Iron Pnictides
• Spin fluctuations and superconductivity in a 3D tight-binding model for BaFe2As2
• Nematic spin correlations in the tetragonal state of uniaxial strained BaFe2-xNixAs2
• Low energy spin waves and magnetic interactions in SrFe${}_2$As${}_2$
• Itinerant magnetic excitations in antiferromagnetic CaFe2As2
• Unconventional electronic reconstruction in undoped (Ba,Sr)Fe${}_2$As${}_2$ across the spin density wave transition
• High energy spin excitations in BaFe2As2
• Neutron Scattering Resonance and the Fe-pnictide Superconducting Gap
• Electronic Structure of Prototype AFe_2As_2 and ReOFeAs High-Temperature Superconductors: a Comparison
• Itinerant Spin Excitations in SrFe2As2 Measured by Inelastic Neutron Scattering
• Spin and Charge Dynamics Ruled by Antiferromagnetic Order in Iron Pnictides
• Spin excitations in the nematic phase and the metallic stripe spin-density wave phase of iron pnictides
• Fermionic representation for the ferromagnetic Kondo lattice model -- diagrammatic study of spin-charge coupling effects on magnon excitations
• Electronic structure, spin excitations, and orbital ordering in a three-orbital model for iron pnictides

Cited by in corpus (3)

• Valley-polarized magnetoconductivity and particle-hole symmetry breaking in a periodically modulated $\alpha$-${\mathcal{T}}_3$ lattice
• Spin-wave excitations in the SDW state of iron pnictides: a comparison between the roles of interaction parameters
• Spin-wave excitations in the SDW state of doped iron pnictides