Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of fluctuation-induced tunneling conduction in
  micrometer-sized tunnel junctions   Micrometer-sized Al/AlO$_{x}$/Y tunnel junctions were fabricated by the
electron-beam lithography technique. The thin ($\approx$ 1.5--2 nm thickness)
insulating AlO$_{x}$ layer was grown on top of the Al base electrode by O$_{2}$
glow discharge. The zero-bias conductances $G(T)$ and the current-voltage
characteristics of the junctions were measured in a wide temperature range
1.5--300 K\@. In addition to the direct tunneling conduction mechanism observed
in low-$G$ junctions, high-$G$ junctions reveal a distinct charge transport
process which manifests the thermally fluctuation-induced tunneling conduction
(FITC) through short nanoconstrictions. We ascribe the experimental realization
of the FITC mechanism to originating from the formations of "hot spots"
(incomplete pinholes) in the AlO$_{x}$ layer owing to large junction-barrier
interfacial roughness.

2
The categories of this paper are: math
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th