Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Defect solitons supported by nonlocal PT symmetric superlattices   The existence and stability of defect solitons supported by parity-time (PT)
symmetric superlattices with nonlocal nonlinearity are investigated. In the
semi-infinite gap, in-phase solitons are found to exist stably for positive or
zero defects, but can not exist in the presence of negative defects with strong
nonlocality. In the first gap, out-of-phase solitons are stable for positive or
zero defects, whereas in-phase solitons are stable for negative defects. The
dependence of soliton stabilities on modulation depth of the PT potentials is
studied. It is interesting that solitons can exist stably for positive and zero
defects when the PT potentials are above the phase transition points.

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The categories of this paper are: hep-th
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The categories of this paper are: eess
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The categories of this paper are: q-fin
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The categories of this paper are: solv-int
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The categories of this paper are: quant-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: cmp-lg
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-ex