Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Investigation of vortex dynamics in Josephson junction arrays with
  magnetic flux noise measurements   We have measured the magnetic flux noise in a two-dimensional Josephson
junction array in nominally zero magnetic field, in the vicinity of the
superconducting transition. This transition is of the
Berezinski-Kosterlitz-Thouless (BKT) type, driven by the unbinding of thermally
excited vortex-antivortex pairs. At temperatures just above the BKT transition
temperature $T_{c}$, the flux-noise power spectrum $S(\omega)$ is white up to a
temperature dependent cross-over frequency $\omega_{\xi}(T)$. We identify
$\omega_{\xi}$ with the characteristic time related to the scale at which the
cross-over from free vortex response to a response dominated by bound pairs
occurs. The signature of free vortices is thus white noise while bound vortex
pairs give rise to a $1/\omega$ dependence.

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The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
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The categories of this paper are: supr-con
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The categories of this paper are: eess
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
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The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat