Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analysis of low-field isotropic vortex glass containing vortex groups in
  YBCO thin films visualized by scanning SQUID microscopy   The glass-like vortex distribution in pulsed laser deposited YBCO thin films
is observed by scanning superconducting quantum interference device microscopy
and analysed for ordering after cooling in magnetic fields significantly
smaller than the Earth's field. Autocorrelation calculations on this
distribution show a weak short-range positional order, while Delaunay
triangulation shows a near-complete lack of orientational order. The
distribution of these vortices is finally characterised as an isotropic vortex
glass. Abnormally closely spaced groups of vortices, which are statistically
unlikely to occur, are observed above a threshold magnetic field. The origin of
these groups is discussed, but will require further investigation.

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The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
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The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th