Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Efficient retrieval of a single excitation stored in an atomic ensemble   We report significant improvements in the retrieval efficiency of a single
excitation stored in an atomic ensemble and in the subsequent generation of
strongly correlated pairs of photons. A 50% probability to transform the stored
excitation into one photon in a well-defined spatio-temporal mode at the output
of the ensemble is demonstrated. These improvements are illustrated by the
generation of high-quality heralded single photons with a suppression of the
two-photon component below 1% of the value for a coherent state. A broad
characterization of our system is performed for different parameters in order
to provide input for the future design of realistic quantum networks.

9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an