Symmetry-protected exceptional rings in two-dimensional correlated systems

ORAL

Abstract

Emergence of exceptional points in two-dimensional systems is one of the characteristic phenomena in non-Hermitian systems. In this talk, we elucidate the impacts of symmetry on the non-Hermitian degeneracies. In particular, we analyze correlated systems with chiral symmetry in equilibrium where the imaginary-part of the self-energy induces the non-Hermitian phenomenon. Intriguingly, our analysis discover novel topological degeneracies which we call symmetry-protected exceptional rings (SPERs). Furthermore, we demonstrate that SPERs emerge in a correlated honeycomb lattice by employing the dynamical mean-field theory combined with the numerical renormalization group.

*This work is partly supported by JSPS KAKENHI Grants No. JP15H05855, No. JP16K05501, No. JP16K13845, No. JP17H06138, No. JP18H01140, No. JP18H04316, No. JP18K03511, and No. JP18H05842. The numerical calculations were performed on supercomputer at the ISSP in the University of Tokyo, and the SR16000 at YITP in Kyoto University.

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Presenters

  • Tsuneya Yoshida

    • University of Tsukuba
    • Department of Physics, University of Tsukuba

Authors

  • Tsuneya Yoshida

    • University of Tsukuba
    • Department of Physics, University of Tsukuba

  • Robert Peters

    • Kyoto University
    • Department of Physics, Kyoto University

  • Norio Kawakami

    • Department of Physics, Kyoto University
    • Kyoto University

  • Yasuhiro Hatsugai

    • University of Tsukuba
    • Department of Physics, University of Tsukuba