Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Can the conductance of an adiabatic ballistic constriction be lower than
  $2e^2/h$?   We have performed four-terminal conductance measurements of a one-dimensional
(1D) channel in which it is possible to modulate the potential profile using
three overlaying finger gates. In such a 1D ballistic structure we have
observed, {\em for the first time,} that the conductance steps show a gradual
decrease from $2e^2/h$ to $0.97 \times 2e^2/h$ with increasing negative finger
gate voltage in a short, clean 1D constriction. We suggest this phenomenon is
due to differing shifts of 1D subbands with changing spilt-gate voltage. Both a
simple analytical estimate for an adiabatic constriction and, realistic
modeling of the device, give the same magnitude of the conductance decrease as
observed in our experiments.

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The categories of this paper are: cs
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The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
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The categories of this paper are: nlin
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The categories of this paper are: q-fin
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The categories of this paper are: hep-ex
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The categories of this paper are: adap-org
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The categories of this paper are: math
30
The categories of this paper are: q-alg
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The categories of this paper are: solv-int
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The categories of this paper are: stat