Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analysing surface structures on (Ga,Mn)As by Atomic Force Microscopy   Using atomic force microscopy, we have studied the surface structures of high
quality molecular beam epitaxy grown (Ga,Mn)As compound. Several samples with
different thickness and Mn concentration, as well as a few (Ga,Mn)(As,P)
samples have been investigated. All these samples have shown the presence of
periodic ripples aligned along the $[1\bar{1}0]$ direction. From a detailed
Fourier analysis we have estimated the period (~50 nm) and the amplitude of
these structures.

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The categories of this paper are: cmp-lg
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The categories of this paper are: eess
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The categories of this paper are: chem-ph
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The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
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The categories of this paper are: nlin
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The categories of this paper are: plasm-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: econ
10
The categories of this paper are: q-bio
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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn