Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multigap superconductivity in sesquicarbides La$_2$C$_3$ and Y$_2$C$_3$   A complex structure of the superconducting order parameter in $Ln_2$C$_3$
($Ln$ = La, Y) is demonstrated by muon spin relaxation ($\mu$SR) measurements
in their mixed state. The muon depolarization rate [$\sigma_{\rm v}(T)$]
exhibits a characteristic temperature dependence that can be perfectly
described by a phenomenological double-gap model for nodeless
superconductivity. While the magnitude of two gaps is similar between
La$_2$C$_3$ and Y$_2$C$_3$, a significant difference in the interband coupling
between those two cases is clearly observed in the behavior of $\sigma_{\rm
v}(T)$.

2
The categories of this paper are: math
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin