Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Collective Charge Excitation in a Dimer Mott Insulating System   Charge dynamics in a dimer Mott insulating system, where a non-polar
dimer-Mott (DM) phase and a polar charge-ordered (CO) phase compete with each
other, are studied. In particular, collective charge excitations are analyzed
in the three different models where the internal-degree of freedom in a dimer
is taken into account. Collective charge excitation exists both in the
non-polar DM phase and the polar CO phase, and softens in the phase boundary.
This mode is observable by the optical conductivity spectra where the light
polarization is parallel to the electric polarization in the polar CO phase.
Connections between the present theory and the recent experimental results in
kappa-(BEDT-TTF)2Cu2(CN)3 are discussed.

9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
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The categories of this paper are: nucl-th
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys