Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Comment on " Low-Lying Quasiparticle States and Hidden Collective Charge
  Instabilities in Parent Cobaltate Superconductors"   Qian et al [1] recently reported angular-resolved photoemission spectroscopy
(ARPES) measurements for Na0.8CoO2 that show two concentric Fermi surfaces (FS)
split by a delta k_F that varies by a factor of three around the Brillouin zone
(BZ). The surfaces occupy 70+/-5% of the full 2D BZ and were interpreted as the
bonding and antibonding splitting (BAS) of the a1g bands, with an unspecified
effect of magnetic ordering. Below we show that this interpretation is not
possible, and, in fact, no valid intepretation of the observed spectra in terms
of the bulk electronic structure of Na0.8CoO2 can be found.

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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
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The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: q-alg
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The categories of this paper are: solv-int
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The categories of this paper are: nlin
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: eess
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The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph