Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Is magnetic flux quantized inside a solenoid?   In some textbooks on quantum mechanics, the description of flux quantization
in a superconductor ring based on the Aharonov-Bohm effect may lead some
readers to a (wrong) conclusion that flux quantization occurs as well for a
long solenoid with the same quantization condition in which the charge of
cooper pair $2e$ is replaced by the charge of one electron $e$. It is shown how
this confusion arises and how can one avoid it.

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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: adap-org
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The categories of this paper are: hep-ex
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The categories of this paper are: eess
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The categories of this paper are: gr-qc
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The categories of this paper are: math
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The categories of this paper are: atom-ph
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The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-th
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The categories of this paper are: acc-phys
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The categories of this paper are: econ
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: ao-sci