Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low-energy excitation spectra in the excitonic phase of cobalt oxides   We study the excitonic phase and low-energy excitation spectra of perovskite
cobalt oxides. Constructing the five-orbital Hubbard model defined on the
three-dimensional cubic lattice for the $3d$ bands of
Pr$_{0.5}$Ca$_{0.5}$CoO$_3$, we calculate the excitonic susceptibility in the
normal state in the random-phase approximation (RPA) to show the presence of
the instability toward excitonic condensation. Based on the excitonic ground
state with a magnetic multipole obtained in the mean-field approximation, we
calculate the dynamical susceptibility of the excitonic phase in the RPA and
find that there appear the gapless collective excitation in the spin-transverse
mode (Goldstone mode) and the gapful collective excitation in the
spin-longitudinal mode (Higgs mode). Experimental relevance is discussed.

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The categories of this paper are: supr-con
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg