Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spontaneous Symmetry Breaking in Photonic Lattices: Theory and
  Experiment   We examine an example of spontaneous symmetry breaking in a double-well
waveguide with a symmetric potential. The ground state of the system beyond a
critical power becomes asymmetric. The effect is illustrated numerically, and
quantitatively analyzed via a Galerkin truncation that clearly shows the
bifurcation from a symmetric to an asymmetric steady state. This phenomenon is
also demonstrated experimentally when a probe beam is launched appropriately
into an optically induced photonic lattice in a photorefractive material.

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The categories of this paper are: ao-sci
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The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin
9
The categories of this paper are: nlin
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The categories of this paper are: math
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The categories of this paper are: econ
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: physics
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The categories of this paper are: hep-lat
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The categories of this paper are: funct-an
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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-ex