Hund's coupling and electronic anisotropy in the spin-density wave state of iron pnictides

Abstract

In the multiband systems, Hund's coupling ($J$) plays a significant role in the spin and charge excitations. We study the dependence of electronic anisotropy on $J$ in terms of Drude-weight along different directions as well as the orbital order in the four-fold symmetry broken spin-density wave state of iron pnictides. A robust behavior of the Drude-weight anisotropy within a small window around $J\sim 0.25U$ with $U$ as intraorbital Coulomb interaction is described in terms of orbital-weight distribution along the reconstructed Fermi surfaces. We also find that the ferro-orbital order increases with $J$ in the widely accepted regime for the latter, which is explained as a consequence of rising exchange field with an increase in magnetization.

6 pages, 3 figures

References in corpus (14)

• 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
• 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
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• Origin of the ~150 K Anomaly in LaOFeAs; Competing Antiferromagnetic Superexchange Interactions, Frustration, and Structural Phase Transition
• Nematic and meta-nematic transitions in the iron pnictides
• Magnetism and Charge Dynamics in Iron Pnictides
• Unprecedented anisotropic metallic state in BaFe2As2 revealed by optical spectroscopy
• Unconventional electronic reconstruction in undoped (Ba,Sr)Fe${}_2$As${}_2$ across the spin density wave transition
• Conductivity anisotropy in the antiferromagnetic state of iron pnictides
• Orbital differentiation and the role of orbital ordering in the magnetic state of Fe superconductors
• Orbital-weight redistribution triggered by spin order in the pnictides
• Optical conductivity and Raman scattering of iron superconductors