Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dirac fermions at the H point of graphite: Magneto-transmission studies   We report on far infrared magneto-transmission measurements on a thin
graphite sample prepared by exfoliation of highly oriented pyrolytic graphite.
In magnetic field, absorption lines exhibiting a blue-shift proportional to
sqrtB are observed. This is a fingerprint for massless Dirac holes at the H
point in bulk graphite. The Fermi velocity is found to be c*=1.02x10^6 m/s and
the pseudogap at the H point is estimated to be below 10 meV. Although the
holes behave to a first approximation as a strictly 2D gas of Dirac fermions,
the full 3D band structure has to be taken into account to explain all the
observed spectral features.

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The categories of this paper are: alg-geom
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The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
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The categories of this paper are: q-fin
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The categories of this paper are: solv-int
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The categories of this paper are: astro-ph
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The categories of this paper are: q-bio
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The categories of this paper are: patt-sol
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The categories of this paper are: nlin
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The categories of this paper are: math
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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: bayes-an
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The categories of this paper are: econ
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The categories of this paper are: supr-con
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The categories of this paper are: chao-dyn