Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Epitaxial aluminium-nitride tunnel barriers grown by nitridation with a
  plasma source   High critical current-density (10 to 420 kA/cm^2)
superconductor-insulator-superconductor tunnel junctions with aluminium nitride
barriers have been realized using a remote nitrogen plasma from an inductively
coupled plasma source operated in a pressure range of 10^{-3} to 10^{-1} mbar.
We find a much better reproducibility and control compared to previous work.
  From the current-voltage characteristics and cross-sectional TEM images it is
inferred that, compared to the commonly used AlO_x barriers, the
poly-crystalline AlN barriers are much more uniform in transmissivity, leading
to a better quality at high critical current-densities.

28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
2
The categories of this paper are: math
18
The categories of this paper are: econ