Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Enhancement of Superfluid Stiffness, Suppression of Superconducting T_c
  and Field-induced Magnetism in the Pnictide Superconductor LiFeAs   Transverse-field muon-spin rotation measurements performed on two samples of
LiFeAs demonstrate that the superfluid stiffness of the superconducting
condensate in relation to its superconducting transition temperature is
enhanced compared to other pnictide superconductors. Evidence is seen for a
field-induced magnetic state in a sample with a significantly suppressed
superconducting transition temperature. The results in this system highlight
the role of direct Fe-Fe interactions in frustrating pairing mediated by
antiferromagnetic fluctuations and suggest that, in common with other pnictide
superconductors, the system is close to a magnetic instability.

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The categories of this paper are: quant-ph
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The categories of this paper are: q-bio
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The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: chao-dyn
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: math
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The categories of this paper are: q-alg
1
The categories of this paper are: cs
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The categories of this paper are: solv-int
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-ex
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con
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The categories of this paper are: plasm-ph