English

Exceptional Topological Insulators

Mesoscale and Nanoscale Physics 2021-10-04 v2 Strongly Correlated Electrons

Abstract

We introduce the exceptional topological insulator (ETI), a non-Hermitian topological state of matter that features exotic non-Hermitian surface states which can only exist within the three-dimensional topological bulk embedding. We show how this phase can evolve from a Weyl semimetal or Hermitian three-dimensional topological insulator close to criticality when quasiparticles acquire a finite lifetime. The ETI does not require any symmetry to be stabilized. It is characterized by a bulk energy point gap, and exhibits robust surface states that cover the bulk gap as a single sheet of complex eigenvalues or with a single exceptional point. The ETI can be induced universally in gapless solid-state systems, thereby setting a paradigm for non-Hermitian topological matter.

Keywords

Cite

@article{arxiv.2008.01090,
  title  = {Exceptional Topological Insulators},
  author = {M. Michael Denner and Anastasiia Skurativska and Frank Schindler and Mark H. Fischer and Ronny Thomale and Tomáš Bzdušek and Titus Neupert},
  journal= {arXiv preprint arXiv:2008.01090},
  year   = {2021}
}

Comments

6+ pages, 3 figures; 21 pages Supplemental Material

R2 v1 2026-06-23T17:36:43.502Z