Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two superconducting gaps in LaFeAsO0.92F0.08 revealed by 75As nuclear
  quadrupole resonance   We report $^{75}$As nuclear quadrupole resonance (NQR) studies on
superconducting oxypnictide LaFeAsO$_{0.92}$F$_{0.08}$ ($T_{\rm c}$ = 23 K).
The temperature dependence of the spin lattice relaxation rate (1/$T_1$)
decreases below $T_{\rm c}$ without a coherence (Hebel-Slichter) peak and shows
a temperature dependence that is not simple power-law nor exponential. We show
that the result can be understood in terms of two superconducting gaps of
either $d$- or ${\pm}s$-wave symmetry, with the larger gap $\Delta_1\sim 4
k_{\rm B}T_{\rm c}$ and the smaller one $\Delta_2 \sim 1.5 k_{\rm B}T_{\rm c}$.
Our result suggests that the multiple-gaps feature is universal in the
oxypnictides superconductors, which is probably associated with the multiple
electronic bands structure in this new class of materials. We also find that
1/$T_1T$ above $T_{\rm c}$ increases with decreasing temperature, which
suggests weak magnetic fluctuations in the normal state.

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The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
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The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
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The categories of this paper are: q-fin
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The categories of this paper are: stat
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The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn
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The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th