Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Symmetry Adapted Coherent States for Three-Level Atoms Interacting with
  One-Mode Radiation   We introduce a combination of coherent states as variational test functions
for the atomic and radiation sectors to describe a system of Na three- level
atoms interacting with a one-mode quantised electromagnetic field, with and
without the rotating wave approximation, which preserves the symmetry presented
by the Hamiltonian. These provide us with the possibility of finding analytical
solutions for the ground and first excited states. We study the properties of
these solutions for the V-configuration in the double resonance condition, and
calculate the expectation values of the number of photons, the atomic
populations, the total number of excitations, and their corresponding
fluctuations. We also calculate the photon number distribution and the linear
entropy of the reduced density matrix to estimate the entanglement between
matter and radiation. For the first time, we exhibit analytical expressions for
all of these quantities, as well as an analytical description for the phase
diagram in parameter space, which distinguishes the normal and collective
regions, and which gives us all the quantum phase transitions of the ground
state from one region to the other as we vary the interaction parameters (the
matter-field coupling constants) of the model, in functional form.

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The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: solv-int
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The categories of this paper are: hep-th
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The categories of this paper are: bayes-an
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The categories of this paper are: q-fin