Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two-dimensional skyrmions and other solitonic structures in
  confinement-frustrated chiral nematics   We explore spatially localized solitonic configurations of a director field,
generated using optical realignment and laser-induced heating, in frustrated
chiral nematic liquid crystals confined between substrates with perpendicular
surface anchoring. We demonstrate that, in addition to recently studied torons
and Hopf-fibration solitonic structures (hopfions), one can generate a host of
other axially symmetric stable and metastable director field configurations
where local twist is matched to the surface boundary conditions through
introduction of point defects and loops of singular and nonsingular
disclinations. The experimentally demonstrated structures include the so-called
"baby-skyrmions" in the form of double twist cylinders oriented perpendicular
to the confining substrates where their double twist field configuration is
matched to the perpendicular boundary conditions by loops of twist
disclinations. We also generate complex textures with arbitrarily large
skyrmion numbers. A simple back-of-the-envelope theoretical analysis based on
free energy considerations and the nonpolar nature of chiral nematics provides
insights into the long-term stability and diversity of these inter-related
solitonic field configurations, including different types of torons,
cholestric-finger loops, two-dimensional skyrmions, and more complex structures
comprised of torons, hopfions, and various disclination loops that are
experimentally observed in a confinement-frustrated chiral nematic system.

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The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-bio
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The categories of this paper are: acc-phys
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-ex
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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: alg-geom
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The categories of this paper are: math-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-th
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-th