Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Driven Rydberg atoms reveal quartic level repulsion   The dynamics of Rydberg states of a hydrogen atom subject simultaneously to
uniform static electric field and two microwave fields with commensurate
frequencies is considered in the range of small fields amplitudes. In the
certain range of the parameters of the system the classical secular motion of
the electronic ellipse reveals chaotic behavior. Quantum mechanically, when the
fine structure of the atom is taken into account, the energy level statistics
obey predictions appropriate for the symplectic Gaussian random matrix
ensemble.

17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
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The categories of this paper are: eess
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex