Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-Hermitian topological phase transitions for quantum spin Hall
  insulators   The interplay between non-Hermiticity and topology opens an exciting avenue
for engineering novel topological matter with unprecedented properties. While
previous studies have mainly focused on one-dimensional systems or Chern
insulators, here we investigate topological phase transitions to/from quantum
spin Hall (QSH) insulators driven by non-Hermiticity. We show that a trivial to
QSH insulator phase transition can be induced by solely varying non-Hermitian
terms, and there exists exceptional edge arcs in QSH phases. We establish two
topological invariants for characterizing the non-Hermitian phase transitions:
i) with time-reversal symmetry, the biorthogonal $\mathbb{Z}_2$ invariant based
on non-Hermitian Wilson loops, and ii) without time-reversal symmetry, a
biorthogonal spin Chern number through biorthogonal decompositions of the Bloch
bundle of the occupied bands. These topological invariants can be applied to a
wide class of non-Hermitian topological phases beyond Chern classes, and
provides a powerful tool for exploring novel non-Hermitian topological matter
and their device applications.

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The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs