First-principles calculation of the electronic nematicity in FeSe

POSTER

Abstract

We report a density functional theory calculation that produces the nonmagnetic electronic nematic state in FeSe, without explicit breaking of the tetragonal lattice symmetry. We incorporate orbital-resolved interactions by +U and hybrid functional, and precondition the initial wavefunction to find local energy minima with spontaneous symmetry breaking. The lowest-energy nematic state we find features an anti-ferro hexadecapolar charge order, instead of a simple ferro-orbital order, which is important to produce the correct Fermi surface topology in FeSe. We propose that the weak inversion symmetry breaking induced by this multipolar order can be detected by high-precision measurement of the band dispersion as well as second-harmonic generation.

*NSFC Grant No. 11774196, Tsinghua University Initiative Scientific Research Program, National Key Research and Development Program of China (Grand No. 2017YFA0302904).

Presenters

  • Xuanyu Long

    • Institute for Advanced Study, Tsinghua University

Authors

  • Xuanyu Long

    • Institute for Advanced Study, Tsinghua University

  • Shunhong Zhang

    • ICQD, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China
    • ICQD, University of Science and Technology of China
    • International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, and Synergetic Innovation Center of
    • University of Science and Technology of China
    • University of Science and Technology of China, Hefei 230026, China

  • Fa Wang

    • International Center for Quantum Materials, School of Physics, Peking University
    • Peking Univ

  • Zheng Liu

    • Institute for Advanced Study, Tsinghua University