Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Characterization of Parity-Time Symmetry in Photonic Lattices Using
  Heesh-Shubnikov Group Theory   We investigate the properties of parity-time symmetric periodic photonic
structures using Heesh-Shubnikov group theory. Classical group theory cannot be
used to categorize the symmetry of the eigenmodes because the time-inversion
operator is antiunitary. Fortunately, corepresentations of Heesh-Shubnikov
groups have been developed to characterize the effect of antiunitary operators
on eigenfunctions. Using the example structure of a one-dimensional photonic
lattice, we identify the corepresentations of eigenmodes at both low and high
symmetry points in the photonic band diagram. We find that thresholdless
parity-time transitions are associated with particular classes of
corepresentations. The approach is completely general and can be applied to
parity-time symmetric photonic lattices of any dimension. The predictive power
of this approach provides a powerful design tool for parity-time symmetric
photonic device design.

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The categories of this paper are: math
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The categories of this paper are: eess
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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: q-fin
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The categories of this paper are: dg-ga
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The categories of this paper are: gr-qc
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The categories of this paper are: mtrl-th
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The categories of this paper are: nlin
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
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The categories of this paper are: hep-th
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The categories of this paper are: hep-ph
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The categories of this paper are: q-alg