The Hopf insulator is a three-dimensional topological insulator outside the standard
classification of topological insulators. Here we consider two types of non-Hermitian Hopf …

The Hopf insulator is a representative class of three-dimensional topological insulators
beyond the standard topological classification methods based on K theory. In this Letter, we …

A d-dimensional second-order topological insulator (SOTI) can host topologically protected
(d-2)-dimensional gapless boundary modes. Here, we show that a 2D non-Hermitian SOTI …

A non-Hermitian topological insulator with a real spectrum is interesting in the theory of non-
Hermitian extension of topological systems. We find an experimentally realizable example of …

Two-band model works well for Hall effect in topological insulators. It turns out to be non-
Hermitian when the system is subjected to environments, and its topology characterized by …

Spectra of bulk or edges in topological insulators are often made complex by non-
Hermiticity. Here, we show that symmetry protection enables entirely real spectra for both …

Second-order topological insulator (SOTI) is featured with the presence of (d− 2)-
dimensional boundary states in d-dimension systems. The non-Hermiticity induced …

We consider a non-Hermitian (NH) analog of a second-order topological insulator, protected
by chiral symmetry, in the presence of next-nearest-neighbor hopping elements to …

In two-dimensional anomalous Floquet insulators, non-Hermitian boundary state
engineering can be used to completely separate chiral boundary states from bulk bands in …

A scenario of non-Hermitian bulk–boundary correspondence proposed for one-dimensional
topological insulators is adapted to a non-Hermitian Chern insulator to examine its …