Frustrated magnetism and bicollinear antiferromagnetic order in FeTe

ORAL

Abstract

Iron chalcogenides display a variety of electronic orders in their phase diagram. A particularly enigmatic case is FeTe, a metal with co-existing hole and electron Fermi surfaces as in the iron pnictides but has a distinct (pi/2,pi/2) bicollinear (BC) antiferromagnetic order. While local-moment physics has been recognized as essential for the electronic order in FeTe, it has been a long-standing challenge to understand how the bicollinear antiferromagnetic ground state emerges in a proper quantum spin model. We demonstrate that a bilinear-biquadratic spin-1 model on a square lattice harbors the BC order that is quasi-degenerate with the (pi/2, pi/2) plaquette (PL) order over an extended parameter regime [1], but the ring-exchange interactions stabilize the BC order. Recently, it became possible to test our theory in the polarized neutron scattering experiment [2]. This in turn motivated us to calculate the dynamic spin structure factors for the BC and PL orders. We discuss the implications for the overall understanding of the magnetism in the iron-based systems. [1] H.-H. Lai, S.-S. Gong, W.-J. Hu, Q. Si, arXiv:1608.08206. [2] Y. Song et al., preprint (2017).

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Presenters

  • Hsin-Hua Lai

    Department of Physics and Astronomy, Rice University, Rice Univ, Physics and Astronomy, and Rice Center for Quantum Materials, Rice University, Department of Physics and Astronomy, Rice Univ

Authors

  • Hsin-Hua Lai

    Department of Physics and Astronomy, Rice University, Rice Univ, Physics and Astronomy, and Rice Center for Quantum Materials, Rice University, Department of Physics and Astronomy, Rice Univ

  • Shoushu Gong

    Department of Physics, Beihang University, Beihang University, National High Magnetic Field Laboratory

  • Wenjun Hu

    Department of Physics and Astronomy, Rice University, Rice Univ, Department of Physics and Astronomy, Rice Univ

  • Qimiao Si

    Department of Physics and Astronomy, Rice University, Physics and Astronomy, Rice Univ, Physics and Astronomy, Rice University, Rice Univ, Rice Universiry, Physics, Rice University, Rice University, Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Physics and Astronomy, and Rice Center for Quantum Materials, Rice University, Department of Physics and Astronomy, Rice Univ