Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Doubly resonant ultrachirped pulses   Ultrachirped pulses for which the frequency chirp is of the order of the
transition frequency of a two-level atom are examined. When the chirp is large
enough, the resonance may be crossed twice, for positive and negative
quadrature frequencies. In this scenario the analytic signal and quadrature
decompositions of the field into amplitude and phase factors turn out to be
quite different. The corresponding interaction pictures are strictly
equivalent, but only as long as approximations are not applied. The domain of
validity of the formal rotating wave approximation is dramatically enhanced
using the analytic signal representation.

37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph