Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Real spectra in non-Hermitian topological insulators   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 bulk and edges even in non-Hermitian topological insulators.
In particular, we demonstrate entirely real spectra without non-Hermitian skin
effects due to a combination of pseudo-Hermiticity and Kramers degeneracy. This
protection relies on nonspatial fundamental symmetry and has stability against
disorder. As an illustrative example, we investigate a non-Hermitian extension
of the Bernevig-Hughes-Zhang model. The helical edge states exhibit oscillatory
dynamics due to their nonorthogonality as a unique non-Hermitian feature.

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The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
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The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
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The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci