Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The role of the coherence length for the establishment of global phase
  coherence in three-dimensional arrays of ultra-thin quasi-one-dimensional
  superconducting Pb and NbN nanowires   We have fabricated 5 nm ultra-thin NbN nanowires that form a dense and
regular array in the linear channels of mesoporous SBA-15 silica substrates.
Bulk NbN is a well-known classical superconductor with Tc of 16 K. We show
that, by being incorporated into this nanostructure, the composite material
exhibits typical quasi-one-dimensional characteristics. We compare the
superconducting properties with those of superconducting Pb nanowires of same
dimensionality in identical configuration within the linear SBA-15 pores. While
Pb nanowire arrays show a pronounced crossover from 1D superconductivity at
high temperatures to a 3D bulk superconducting state in the low temperature
regime with true zero resistance triggered by transversal Josephson
interaction, this transition appears to be completely absent in the NbN
nanowire array. The small coherence length in NbN, which strongly suppresses
the Josephson coupling is discussed as the origin of this difference.

19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom