Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exciton Mott transition in Si Revealed by Terahertz Spectroscopy   Exciton Mott transition in Si is investigated by using terahertz time-domain
spectroscopy. The excitonic correlation as manifested by the 1s-2p resonance is
observed above the Mott density. The scattering rate of charge carriers is
prominently enhanced at the proximity of Mott density, which is attributed to
the non-vanishing exciton correlation in the metallic electron-hole plasma.
Concomitantly, the signature of plasmon-exciton coupling is observed in the
loss function spectra.

34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
2
The categories of this paper are: math
3
The categories of this paper are: physics
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The categories of this paper are: adap-org
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The categories of this paper are: eess
20
The categories of this paper are: acc-phys
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The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
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The categories of this paper are: comp-gas
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The categories of this paper are: supr-con
23
The categories of this paper are: solv-int