Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Attenuation and amplification of the transient current in nanojunctions
  with time-varying gate potentials   We study charge transport in a source-channel-drain system with a
time-varying applied gate potential acting on the channel. We calculate both
the current flowing from the source into the channel and out of the channel
into the drain. The current is expressed in terms of nonequilibrium Green's
functions. These nonequilibrium Green's functions can be determined from the
steady-state Green's functions and the equilibrium Green's functions of the
free leads. We find that the application of the gate potential can induce
current to flow even when there is no source-drain bias potential. However, the
direction of the current from the source and the current to the drain are
opposite, thereby resulting in no net current flowing within the channel. When
a source-drain bias potential is present, the net current flowing to the source
and drain can either be attenuated or amplified depending on the sign of the
applied gate potential. We also find that the response of the system to a
dynamically changing gate potential is not instantaneous, i.e., a relaxation
time has to pass before the current settles into a steady value. In particular,
when the gate potential is in the form of a step function, the current first
overshoots to a maximum value, oscillates, and then settles down to a
steady-state value.

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The categories of this paper are: q-alg
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The categories of this paper are: physics
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The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: funct-an
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The categories of this paper are: math
13
The categories of this paper are: quant-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: math-ph
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The categories of this paper are: solv-int
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The categories of this paper are: q-fin
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The categories of this paper are: patt-sol
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The categories of this paper are: stat