Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum correlations by four-wave mixing in an atomic vapor in a
  non-amplifying regime: a quantum beam splitter for photons   We study the generation of intensity quantum correlations using four-wave
mixing in a rubidium vapor. The absence of cavity in these experiments allows
to deal with several spatial modes simultaneously. In the standard, amplifying,
configuration, we measure relative intensity squeezing up to 9.2 dB below the
standard quantum limit. We also theoretically identify and experimentally
demonstrate an original regime where, despite no overall amplification, quantum
correlations are generated. In this regime a four-wave mixing set-up can
therefore play the role of a photonic beam splitter with non--classical
properties, i.e. a device that splits a coherent state input into two quantum
correlated beams.

32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th