Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fractional quantum Hall effect in higher Landau levels   We investigate, using finite size numerical calculations, the spin-polarized
fractional quantum Hall effect (FQHE) in the first excited Landau level (LL).
We find evidence for the existence of an incompressible state at $\nu =
\frac{7}{3} = 2+\frac{1}{3}$, but not at $\nu = 2+\frac{2}{5}$. Surprisingly,
the 7/3 state is found to be strongest at a finite thickness. The structure of
the low- lying excited states is found to be markedly different from that in
the lowest LL. This study also rules out FQHE at a large number of
odd-denominator fractions in the lowest LL.

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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: ao-sci
7
The categories of this paper are: hep-th
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The categories of this paper are: chem-ph
19
The categories of this paper are: eess
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The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
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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: adap-org
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The categories of this paper are: q-fin
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The categories of this paper are: math
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The categories of this paper are: chao-dyn
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The categories of this paper are: econ
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The categories of this paper are: q-bio