Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modulation of Electrical Conduction Through Individual Molecules on
  Silicon by the Electrostatic Fields of Nearby Polar Molecules: Theory and
  Experiment   We report on the synthesis, scanning tunneling microscopy (STM) and
theoretical modeling of the electrostatic and transport properties of
one-dimensional organic heterostructures consisting of contiguous lines of CF3-
and OCH3-substituted styrene molecules on silicon. The electrostatic fields
emanating from these polar molecules are found, under appropriate conditions,
to strongly influence electrical conduction through nearby molecules and the
underlying substrate. For suitable alignment of the OCH3 groups of the
OCH3-styrene molecules in the molecular chain, their combined electric fields
are shown by ab initio density functional calculations to give rise to
potential profiles along the OCH3-styrene chain that result in strongly
enhanced conduction through OCH3-styrene molecules near the heterojunction for
moderately low negative substrate bias, as is observed experimentally. Under
similar bias conditions, dipoles associated with the CF3 groups are found in
both experiment and in theory to depress transport in the underlying silicon.
Under positive substrate bias, simulations suggest that the differing
structural and electrostatic properties of the CF3-styrene molecules may lead
to a more sharply localized conduction enhancement near the heterojunction at
low temperatures. Thus choice of substituents, their attachment site on the
host styrene molecules on silicon and the orientations of the molecular dipole
and higher multipole moments provide a means of differentially tuning transport
on the molecular scale.

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The categories of this paper are: comp-gas
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The categories of this paper are: cmp-lg
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The categories of this paper are: mtrl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: hep-lat
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The categories of this paper are: math
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The categories of this paper are: nucl-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: physics
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-bio
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The categories of this paper are: q-alg
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-th