Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Highly Conducting pi-Conjugated Molecular Junctions Covalently Bonded to
  Gold Electrodes   We measure electronic conductance through single conjugated molecules bonded
to Au metal electrodes with direct Au-C covalent bonds using the scanning
tunneling microscope based break-junction technique. We start with molecules
terminated with trimethyltin end groups that cleave off in situ resulting in
formation of a direct covalent sigma bond between the carbon backbone and the
gold metal electrodes. The molecular carbon backbone used in this study consist
of a conjugated pi-system that has one terminal methylene group on each end,
which bonds to the electrodes, achieving large electronic coupling of the
electrodes to the pi-system. The junctions formed with the prototypical example
of 1,4-dimethylenebenzene show a conductance approaching one conductance
quantum (G0 = 2e2/h). Junctions formed with methylene terminated oligophenyls
with two to four phenyl units show a hundred-fold increase in conductance
compared with junctions formed with amine-linked oligophenyls. The conduction
mechanism for these longer oligophenyls is tunneling as they exhibit an
exponential dependence of conductance with oligomer length. In addition,
density functional theory based calculations for the Au-xylylene-Au junction
show near-resonant transmission with a cross-over to tunneling for the longer
oligomers.

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The categories of this paper are: math
26
The categories of this paper are: bayes-an
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The categories of this paper are: q-fin
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The categories of this paper are: alg-geom
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The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
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The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
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The categories of this paper are: cs
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The categories of this paper are: chem-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: cmp-lg