Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum effects of operator time ordering in the nonlinear
  Jaynes-Cummings model   Recently, in [Phys. Rev. A 97, 043806 (2018)], the detuned and nonlinear
Jaynes-Cummings model describing the quantized motion of a trapped ion was
introduced and its corresponding dynamics was solved via considering the
driving laser in a quantized manner. In this work we reconsider this model and
show that it can likewise be solved with a classical driving laser field. Using
the exact solution we investigate the quantum time-ordering effects of the
system with respect to nonclassicality of the motional states of the ion.
Furthermore, we use the Magnus expansion to analyze the impact of certain
orders of the time ordering and derive and exact radius of convergence beyond
the established and only sufficient criterion. Finally, the differences of the
solution derived here and the previously found one using a quantized pump, are
discussed.

1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat