Prediction of exotic magnetic states in quasi-one-dimensional iron selenide compound Na<sub>2</sub>FeSe<sub>2</sub>

ORAL

Abstract

Motivated by recent progress in preparing alkali-metal compounds, we present the magnetic and
electronic phase diagram of the quasi-one-dimensional alkali metal iron selenide Na2FeSe2 . The
novelty of this material is that it has both a dominant chain geometry in the structure and the valence of iron is Fe2+.
We derive a realistic three-orbital tight-binding model based on ab initio calculations. We have constructed the ground-state phase diagram for Na2FeSe2, using density-matrix-renormalization group and Lanczos methods. We find a robust region of block state, with two-spin ferromagnetic clusters coupled antiferromagnetically. The phase diagram also contains a large region of staggered spin order at large Hubbard repulsion. In addition to these phases, near the block-to-staggered transition region, an exotic phase is stabilized with a mixture of both states: an inhomogeneous orbital-selective charge density wave with the exotic spin configuration. Our predictions for Na2FeSe2, should be of interest to both theorists and experimentalists working on the realization of block states in one-dimensional iron selenide chain materials.

*This work was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy
Sciences (BES), Materials Sciences and Engineering Division.

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Presenters

  • bradraj pandey

    • University of Tennessee

Authors

  • bradraj pandey

    • University of Tennessee

  • Ling-Fang Lin

    • University of Tennessee

  • Rahul Soni

    • University of Tennessee
    • Department of Physics and Astronomy, University of Tennessee

  • Nitin Kaushal

    • Center for Nanophase Materials Sciences, Oak Ridge National Laboratory
    • University of Tennessee

  • Jacek Herbrych

    • Wroclaw Univ of Tech
    • Wroclaw University of Science and Technology
    • Department of Theoretical Physics, Wroclaw University of Science and Technology

  • Gonzalo Alvarez

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory
    • Computational Sciences and Engineering Division, Oak Ridge National Laboratory
    • Center for Nanophase Materials Sciences, Oak Ridge National Laboratory
    • Computational Sciences & Engineering Division and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory
    • Computational Sciences and Engineering Division and Center for Nanophase Materials Sciences, Oak Ridge National Laboratory

  • Elbio Dagotto

    • University of Tennessee
    • Department of Physics and Astronomy, University of Tennesse at Knoxville
    • Physics, University of Tennessee
    • University of Tennessee and ORNL
    • Department of Physics and Astronomy, University of Tennessee
    • Oak Ridge National Lab