Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electric field gradient induced effects in GaAs/AlGaAs modulation-doped
  structures and high frequency sensing   Electric field gradient effects induced by an asymmetrically in-plane shaped
GaAs/AlGaAs modulation-doped structures of various design are investigated
within 4-300 K temperature range. It is demonstrated that current-voltage
characteristics of such structures at low, 4-80 K, temperatures exhibit
well-pronounced asymmetry arising due to a presence of two different gradients
of the electric field in a two dimensional electron gas. This phenomenon is
caused by both, different accumulation of two-dimensional electrons due to
asymmetrical shape of the structure and nonlocality in the electron drift
velocity. Experiments are illustrated by a phenomenological model and Monte
Carlo simulation. Possible applications of the effect to detect electromagnetic
radiation of GHz and THz frequencies are discussed as well.

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The categories of this paper are: math-ph
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The categories of this paper are: stat
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The categories of this paper are: nucl-th
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
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The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
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The categories of this paper are: funct-an
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph