Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evidence for two-gap nodeless superconductivity in
  SmFeAsO$_{0.8}$F$_{0.2}$ from point-contact Andreev-reflection spectroscopy   Point-contact Andreev-reflection measurements were performed in
SmFeAsO_{0.8}F_{0.2} polycrystals with T_c \simeq 53 K. The experimental
conductance curves reproducibly exhibit peaks around \pm 6 mV and shoulders at
V \sim 16-20 mV, indicating the presence of two nodeless superconducting gaps.
While the single-band Blonder-Tinkham-Klapwijk fit can only reproduce a small
central portion of the conductance curve, the two-gap one accounts remarkably
well for the shape of the whole experimental dI/dV. The fits of the normalized
curves give Delta_1(0) = 6.15 \pm 0.45 meV and Delta_2(0) = 18 \pm 3 meV. Both
gaps close at the same temperature and follow a BCS-like behavior.

30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
2
The categories of this paper are: math