Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Microwave Response of V3Si Single Crystals: Evidence for Two-Gap
  Superconductivity   The investigation of the temperature dependences of microwave surface
impedance and complex conductivity of V3Si single crystals with different
stoichiometry allowed to observe a number of peculiarities which are in
remarkable contradiction with single-gap Bardeen-Cooper-Schrieffer theory. At
the same time, they can be well described by two-band model of
superconductivity, thus strongly evidencing the existence of two distinct
energy gaps with zero-temperature values Delta1~1.8Tc and Delta2~0.95Tc in
V3Si.

28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph