Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Liganded Xene as a Prototype of Two-Dimensional Stiefel-Whitney
  Insulators   Two-dimensional (2D) Stiefel-Whitney insulator (SWI), which is characterized
by the second Stiefel-Whitney class, is a new class of topological phases with
zero Berry curvature. As a novel topological state, it has been well studied in
theory but seldom realized in realistic materials. Here we propose that a large
class of liganded Xenes, i.e., hydrogenated and halogenated 2D group-IV
honeycomb lattices, are 2D SWIs. The nontrivial topology of liganded Xenes is
identified by the bulk topological invariant and the existence of protected
corner states. Moreover, the large and tunable band gap (up to 3.5 eV) of
liganded Xenes will facilitate the experimental characterization of the 2D SWI
phase. Our findings not only provide abundant realistic material candidates
that are experimentally feasible, but also draw more fundamental research
interest towards the topological physics associated with Stiefel-Whitney class
in the absence of Berry curvature.

22
The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
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The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
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The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs