Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spontaneous radiation of a two-level atom into multipole modes of a
  plasmonic nanoparticle   We consider the relaxation of an excited two-level system (TLS) positioned
near a spherical plasmonic nanoparticle (NP). The transition frequency of the
TLS is assumed to coincide with the frequency of the condensation point of NP
plasmonic resonances. We show that the relaxation of the TLS excitation is a
two-step process. Following an initial exponential decay, the TLS breaks in to
Rabi oscillations. Depending upon the distance between the TLS and NP, the
probability of the TLS being in the excited state exhibits either chaotic or
nearly regular oscillations. In the latter case, the eigenfrequency of the
TLS-NP system coincides with one of NP multipole modes.

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The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci