Spin dynamics within the block orbital-selective Mott phase in one dimensional iron chains and ladders

ORAL

Abstract

Iron-based superconductors display a variety of magnetic phases originating in the competition between electronic, orbital, and spin degrees of freedom. Theoretical investigations [1] of the 1D multiorbital Hubbard model revealed the existence of an orbital-selective Mott phase (OSMP) with block spin order, i.e., antiferromagnetically coupled ferromagnetic (FM) spin islands. Recent inelastic neutron scattering experiments on quasi-1D BaFe2Se3 and doped RbFe2Se3 compounds confirm the relevance of the spin-block phases [2-4]. Moreover, the spectrum unveiled exotic features in the dynamical spin structure factor S(q,ω) including a low-energy acoustic mode and a high-energy optical mode. In our work [5] we present the first theoretical study of the S(q,ω) within the block-OSMP using the DMRG method. In agreement with experimental results we find: a dispersive (acoustic) mode for momentum q<π/2, which arises from the dynamics of FM islands, and a dispersion-less (optical) mode for q>π/2 attributed to local block Hund excitations.

[1] J. Rincon et al., Phys. Rev. Lett. 112, 106405 (2014)
[2] M. Wang, et al., Nature Comm. 2, 580 (2011)
[3] M. Wang, et al., Phys. Rev. B 94, 041111(R) (2016)
[4] M. Mourigal, et al., Phys. Rev. Lett. 115, 047401 (2015)
[5] J. Herbrych, et al., In preparation

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Presenters

  • Jacek Herbrych

    Department of Physics and Astronomy, Univ of Tennessee, Knoxville, University of Tennessee, Department of Physics and Astronomy, The University of Tennessee

Authors

  • Jacek Herbrych

    Department of Physics and Astronomy, Univ of Tennessee, Knoxville, University of Tennessee, Department of Physics and Astronomy, The University of Tennessee

  • Nitin Kaushal

    Department of Physics and Astronomy, Univ of Tennessee, Knoxville, University of Tennessee

  • Alberto Nocera

    Univ. of Tennessee, Physics and Astronomy, University of Tennessee, Department of Physics and Astronomy, Univ of Tennessee, Knoxville, University of Tennessee

  • Gonzalo Alvarez

    Oak Ridge National Laboratory, Oak Ridge National Lab, Center for Nanophase Materials Sciences, Oak Ridge National Laboratory

  • Adriana Moreo

    Univ. of Tennessee, Department of Physics and Astronomy, Univ of Tennessee, Knoxville, Univ of Tennessee and ORNL., University of Tennessee, Univ of Tennessee, Knoxville, Department of Physics and Astronomy, University of Tennessee, Knoxville

  • Elbio Dagotto

    Univ. of Tennessee, Physics and Astronomy, University of Tennessee, Department of Physics and Astronomy, Univ of Tennessee, Knoxville, Department of Physics and Astronomy, University of Tennessee, University of Tennessee, University of Tennessee & Oak Ridge National Laboratory, Department of Physics and Astronomy, University of Tennessee, Knoxville