Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topology and Phase Transitions in the Little-Parks Experiment   This is an analytic study of the problem of transitions between normal and
superconducting phases for a sample which encloses a magnetic flux. A
preliminary study of this problem, based on numerical minimization of the free
energy for a particular form of the thickness of the sample, was published in
Phys. Rev. Lett. {\bf 75}, 320 (1995). For a sample of uniform thickness the
order parameter is uniform, but even infinitesimal deviations from uniform
thickness give rise to a singly connected state in which the order parameter
vanishes at a suitable layer, so that the superconducting part does not enclose
the magnetic field. The stability domain of this singly connected state is a
line segment in the magnetic field-temperature plane, delimited by two critical
points. The phase diagram contains several bifurcation lines, which are
systematically analyzed.

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The categories of this paper are: ao-sci
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The categories of this paper are: patt-sol
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The categories of this paper are: gr-qc
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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: plasm-ph
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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: hep-th
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The categories of this paper are: econ
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
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The categories of this paper are: nucl-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: eess
0
The categories of this paper are: hep-ph