Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Percolation-to-hopping crossover in conductor-insulator composites   Here, we show that the conductivity of conductor-insulator composites in
which electrons can tunnel from each conducting particle to all others may
display both percolation and tunneling (i.e. hopping) regimes depending on few
characteristics of the composite. Specifically, we find that the relevant
parameters that give rise to one regime or the other are $D/\xi$ (where $D$ is
the size of the conducting particles and $\xi$ is the tunneling length) and the
specific composite microstructure. For large values of $D/\xi$, percolation
arises when the composite microstructure can be modeled as a regular lattice
that is fractionally occupied by conducting particle, while the tunneling
regime is always obtained for equilibrium distributions of conducting particles
in a continuum insulating matrix. As $D/\xi$ decreases the percolating behavior
of the conductivity of lattice-like composites gradually crosses over to the
tunneling-like regime characterizing particle dispersions in the continuum. For
$D/\xi$ values lower than $D/\xi\simeq 5$ the conductivity has tunneling-like
behavior independent of the specific microstructure of the composite.

10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
2
The categories of this paper are: math
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph