Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Four allotropes of semiconducting layered Arsenic which switch into a
  topological insulator via an electric field: A computational study   We propose four different thermodynamically stable structural phases of
arsenic monolayers based on ab-initio density functional theory calculations
all of which undergo a topological phase transition on application of a
perpendicular electric field. All the four arsenic monolayer allotropes have a
wide band gap, varying from 1.21 eV to 3.0 eV (based on GW calculations), and
in general they undergo a metal-insulator quantum phase transition on
application of uniaxial in-layer strain. Additionally an increasing transverse
electric field induces band-inversion at the {\Gamma} point in all four
monolayer allotropes, leading to a nontrivial topological phase (insulating for
three and metallic for one allotrope), characterized by the switching of the Z2
index, from 0 (before band inversion) to 1 (after band inversion). The
topological phase tuned by the transverse electric field, should support
spin-separated gapless edge states which should manifest in quantum spin Hall
effect.

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The categories of this paper are: adap-org
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The categories of this paper are: q-bio
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-alg
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The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
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The categories of this paper are: chem-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: astro-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: physics