Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fano q-reversal in topological insulator Bi2Se3   We studied magneto-optical response of a canonical topological insulator
Bi$_2$Se$_3$ with the goal of addressing a controversial issue of
electron-phonon coupling. Magnetic-field induced modifications of reflectance
are very pronounced in the infrared part of the spectrum, indicating strong
electron-phonon coupling. This coupling causes an asymmetric line-shape of the
60 cm$^{-1}$ phonon mode, and is analyzed within the Fano formalism. The
analysis reveals that the Fano asymmetry parameter (q) changes sign when the
cyclotron resonance is degenerate with the phonon mode. To the best of our
knowledge this is the first example of magnetic field driven q-reversal.

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The categories of this paper are: hep-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
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The categories of this paper are: dg-ga
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The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an