Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unconventional superconductivity in quasi-one-dimensional
  Rb$_2$Cr$_3$As$_3$   Following the discovery of superconductivity in quasi-one-dimensional
K$_2$Cr$_3$As$_3$ containing [(Cr$_3$As$_3$)$^{2-}$]$_{\infty}$ chains [J. K.
Bao et al., arXiv: 1412.0067 (2014)], we succeeded in synthesizing an analogous
compound, Rb$_2$Cr$_3$As$_3$, which also crystallizes in a hexagonal lattice.
The replacement of K by Rb results in an expansion of $a$ axis by 3\%,
indicating a weaker interchain coupling in Rb$_2$Cr$_3$As$_3$. Bulk
superconductivity emerges at 4.8 K, above which the normal-state resistivity
shows a linear temperature dependence up to 35 K. The estimated upper critical
field at zero temperature exceeds the Pauli paramagnetic limit by a factor of
two. Furthermore, the electronic specific-heat coefficient extrapolated to zero
temperature in the mixed state increases with $\sqrt{H}$, suggesting existence
of nodes in the superconducting energy gap. Hence Rb$_2$Cr$_3$As$_3$ manifests
itself as another example of unconventional superconductor in the
Cr$_3$As$_3$-chain based system.

11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph