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Exceptional topological insulators.

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.

SUBMITTER: Denner MM

PROVIDER: S-EPMC8478920 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature

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Exceptional topological insulators.

Denner M Michael MM Skurativska Anastasiia A Schindler Frank F Fischer Mark H MH Thomale Ronny R Bzdušek Tomáš T Neupert Titus T

Nature communications 20210928 1

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 ...[more]

PMID: 34584085

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