Insulating ferromagnetic state and orbital-selective Mott phases in an iron chain syste

Studies of orbital-selective and magnetic physics in transition metal compounds continue to attract the attention of the condensed matter community. Here, we report a systematic investigation of the quasi-one-dimensional iron chain Ce₂O₂FeSe₂ based on a multiorbital Hubbard model using many-body computer simulations. We focus on the competition between ferromagnetic and antiferromagnetic tendencies and on the complex interplay of hopping amplitudes, Coulomb interactions, Hund’s coupling, crystal-field splitting, and doping effects. Firstly, our calculations and analysis showed that large entanglements between doubly occupied and half-filled orbitals play a key role in stabilizing the insulating ferromagnetic phase [1]. Secondly, with the effect of doping, a variety of exotic electronic and magnetic states, such as orbital-selective Mott phases and magnetic “block” phases, were predicted due to the competition of the many tendencies [2]. Our theoretical phase diagram will hopefully encourage a more detailed experimental study of 1D iron chalcogenide compounds, or related systems.



[1] L.-F. Lin, et al., Phys. Rev. Lett. 127, 077204 (2021).

[2] L.-F. Lin, et al., Phys. Rev. B 105, 075119 (2022).