Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Anisotropic Metal-Insulator Transition in Epitaxial Thin Films   Quantum wells made of simple polyvalent metals represent a novel family of
doped 2D Mott-Hubbard insulators. As scanning tunneling microscopy experiments
show, these systems exhibit an anisotropic form of metal-insulator transition.
Their elementary excitations possess coherent wave-like properties along the
normal axis, and show an incoherent behavior in-plane. The development of such
an anisotropic coherence is most likely related to Coulomb interaction between
localized and delocalized thin film electronic states - 2D Kondo screening.

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The categories of this paper are: q-bio
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The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
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The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
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The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: econ
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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: math
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The categories of this paper are: stat
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas