Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Infrared Signature of the Superconducting State in Pr(2-x)Ce(x)CuO(4)   We measured the far infrared reflectivity of two superconducting
Pr(2-x)Ce(x)CuO(4) films above and below Tc. The reflectivity in the
superconducting state increases and the optical conductivity drops at low
energies, in agreement with the opening of a (possibly) anisotropic
superconducting gap. The maximum energy of the gap scales roughly with Tc as 2
Delta_{max} / kB Tc ~ 4.7. We determined absolute values of the penetration
depth at 5 K as lambda_{ab} = (3300 +/- 700) A for x = 0.15 and lambda_{ab} =
(2000 +/- 300) A for x = 0.17. A spectral weight analysis shows that the
Ferrell-Glover-Tinkham sum rule is satisfied at conventional low energy scales
\~ 4 Delta_{max}.

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The categories of this paper are: bayes-an
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The categories of this paper are: gr-qc
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The categories of this paper are: astro-ph
2
The categories of this paper are: math
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The categories of this paper are: hep-lat
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The categories of this paper are: mtrl-th
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The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
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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: econ
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The categories of this paper are: q-bio
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The categories of this paper are: patt-sol
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The categories of this paper are: ao-sci
3
The categories of this paper are: physics
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The categories of this paper are: alg-geom