Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-Hermitian spatial symmetries and their stabilized exceptional
  topological semimetals   Without the constraint imposed by Hermiticity, non-Hermitian systems enjoy
greater freedom than Hermitian ones. While internal symmetries enriched by
non-Hermiticity have been revealed, the interplay between spatial symmetries
and non-Hermiticity remains to be explored. Here we study non-Hermitian spatial
symmetries -- a class of symmetries that have no counterparts in Hermitian
systems -- and study how exceptional semimetals can be stabilized by these
symmetries. Different from internal ones, spatial symmetries act non-locally in
momentum space and enforce global constraints on quantities at different
momentum locations. We derive general constraints on geometric and topological
invariants imposed by non-Hermitian spatial symmetries, which differ from those
by Hermitian spatial symmetries. With these constraints, we reveal that certain
exceptional manifold is only compatible with and stabilized by non-Hermitian
spatial symmetries but is intrinsically incompatible with Hermitian spatial
symmetries. We illustrate our theory using two three-dimensional (3D) models,
dubbed exceptional unconventional Weyl semimetal and exceptional triple-point
semimetal, respectively. Experimental cold-atom realization of the former is
also proposed.

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The categories of this paper are: hep-lat
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The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: nucl-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: math-ph
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The categories of this paper are: stat