Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photoluminescence and transport in selectively doped p-GaAs/AlGaAs
  quantum wells: manifestation of the upper Hubbard band   By selective doping (Be) of the well and barrier regions of p-GaAs/AlGaAs
structures we have realized the situation where the upper Hubbard band (A+
centers) has been occupied by holes in the equilibrium. We studied temperature
behavior of the Hall effect, variable range hopping conductivity and the
photoluminescence spectra of the corresponding structures. The experimental
data demonstrated that the binding energy of the A+ states significantly
increases with respect to 3D case and strongly depends on well width
(9nm,15nm). The localization radii of the A+ states are of the order of well
widths.

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The categories of this paper are: adap-org
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The categories of this paper are: nucl-th
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
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The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
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The categories of this paper are: econ
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph