201. Insulating magnetism in vacancy-ordered K0.8Fe1.6Se2
- Author
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Chia-Hui Lin, Wei Ku, and Wei-Guo Yin
- Subjects
Condensed Matter::Quantum Gases ,Superconductivity ,Materials science ,Condensed matter physics ,Electronic correlation ,Magnetism ,Mott insulator ,Electronic structure ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Vacancy defect ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,Strongly correlated material - Abstract
We unveil the novel physical origin of the insulating block checkerboard antiferromagnetism in vacancy-ordered K2Fe4Se5. Our first-principles electronic structure analysis reveals its incompatibility with a simple Fermi-surface nesting or Mott insulator scenario, and suggests the picture of coexisting itinerant and localized electronic states. Consistently, we demonstrate that it can be unified with the metallic collinear or bicollinear antiferromagnetism of the vacancy-free parent compounds LaOFeAs, BaFe2As2, or FeTe in the spin-fermion model. These results indicate that the blocking effects of Hund's rule coupling and the resulting electron correlation are crucial to the electronic and magnetic structures of iron-based superconductors.
- Published
- 2012
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