Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photoinduced enhancement of excitonic order in the two-orbital Hubbard
  model   Photoinduced dynamics in an excitonic insulator is studied theoretically by
using a two-orbital Hubbard model on the square lattice where the excitonic
phase in the ground state is characterized by the BCS-BEC crossover as a
function of the interorbital Coulomb interaction. We consider the case where
the order has a wave vector $Q=(0,0)$ and photoexcitation is introduced by a
dipole transition. Within the mean-field approximation, we show that the
excitonic order can be enhanced by the photoexcitation when the system is
initially in the BEC regime of the excitonic phase, whereas it is reduced if
the system is initially in the BCS regime. The origin of this difference is
discussed from behaviors of momentum distribution functions and
momentum-dependent excitonic pair condensation. In particular, we show that the
phases of the excitonic pair condensation have an important role in determining
whether the excitonic order is enhanced or not.

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The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio