Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: London penetration depth and thermal fluctuations in the sulphur hydride
  203 K superconductor   Recently, compressed H$_2$S has been shown to become superconducting at 203 K
under a pressure of 155 GPa. One might expect fluctuations to dominate at such
temperatures. Using the magnetisation critical current, we determine the
ground-state London penetration depth, $\lambda_0$=189 nm, and the
superconducting energy gap, $\Delta_0$=27.8 meV, and find these parameters are
similar to those of cuprate superconductors. We also determine the fluctuation
temperature scale, $T_{\textrm{fluc}}=1470$ K, which shows that, unlike the
cuprates, $T_c$ of the hydride is not limited by fluctuations. This is due to
its three dimensionality and suggests the search for better superconductors
should refocus on three-dimensional systems where the inevitable thermal
fluctuations are less likely to reduce the observed $T_c$.

10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th