Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multi-band $s_{++}$ superconductivity in $\textrm{V}_{3}\textrm{Si}$
  determined from the response to a controlled disorder   The London penetration depth, $\lambda(T)$, was measured in a single crystal
V$_{3}$Si. The superfluid density obtained from this measurement shows a
distinct signature of two almost decoupled superconducting gaps. This alone is
insufficient to distinguish between $s_{\pm}$ and $s_{++}$ pairing states, but
it can be achieved by studying the effect of a controlled non-magnetic disorder
on the superconducting transition temperature, $T_{c}$. For this purpose, the
same $\text{V}_{3}\text{Si}$ crystal was sequentially irradiated by 2.5 MeV
electrons three times, repeating the measurement between the irradiation runs.
A total dose of 10 C/cm$^{2}$ ($6.24\times10^{19}$ electrons/$\textrm{cm}^{2}$)
was accumulated, for which $T_{c}$ has changed from 16.4 K in a pristine state
to 14.7 K (9.3 $\%$). This substantial suppression is impossible for a single
isotropic gap, but also it is not large enough for a sign-changing $s_{\pm}$
pairing state. Our electronic band-structure calculations show how five bands
crossing the Fermi energy can be naturally grouped to support two effective
gaps, not dissimilar from the iron pnictides physics. We analyze the results
using two-gap models for both, $\lambda(T)$ and $T_{c}$, which describe the
data very well. Thus, the experimental results and theoretical analysis provide
strong support for an $s_{++}$ superconductivity with two unequal gaps,
$\Delta_{1}\left(0\right)\approx2.53\;\textrm{meV}$ and
$\Delta_{2}\left(0\right)\approx1.42\;\textrm{meV}$, and a very weak inter-band
coupling in $\text{V}_{3}\text{Si}$ superconductor.

31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat