Magnetic states of the five-orbital Hubbard model for one-dimensional iron-based superconductors

Abstract

The magnetic phase diagrams of models for quasi one-dimensional compounds belonging to the iron-based superconductors family are presented. The five-orbital Hubbard model and the real-space Hartree-Fock approximation are employed, supplemented by density functional theory to obtain the hopping amplitudes. Phase diagrams are constructed varying the Hubbard $U$ and Hund $J$ couplings and at zero temperature. The study is carried out at electronic density (electrons per iron) $n=5.0$, which is of relevance for the already known material TlFeSe${}_2$, and also at $n=6.0$, where representative compounds still need to be synthesized. At $n=5.0$ there is a clear dominance of staggered spin order along the chain direction. At $n=6.0$ and the realistic Hund coupling $J/U=0.25$, the phase diagram is far richer including a variety of ``block'' states involving ferromagnetic clusters that are antiferromagnetically coupled, in qualitative agreement with recent Density Matrix Renormalization Group calculations for the three-orbital Hubbard model in a different context. These block states arise from the competition between ferromagnetic order (induced by double exchange, and prevailing at large $J/U$) and antiferromagnetic order (dominating at small $J/U$). The density of states and orbital compositions of the many phases are also provided.

12 pages, 11 figures

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Cited by in corpus (7)

• Non-local correlations in the orbital selective Mott phase of a one dimensional multi-orbital Hubbard model
• Pairing Tendencies in a Two-orbital Hubbard Model in One Dimension
• Magnetic states of quasi-one-dimensional iron chalcogenide Ba${}_2$FeS${}_3$
• Block orbital-selective Mott insulators: a spin excitation analysis
• Prediction of exotic magnetic states in the alkali metal quasi-one-dimensional iron selenide compound Na${}_2$FeSe${}_2$
• Quantum magnetism of iron-based ladders: Blocks, spirals, and spin flux
• Quasi-one-dimensional spin excitations in the iron pnictide NaFe${}_{0.53}$Cu${}_{0.47}$As