Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonlocal restoration of two-mode squeezing in the presence of strong
  optical loss   We present the experimental realization of a theoretical effect discovered by
Olivares and Paris, in which a pair of entangled optical beams undergoing
independent losses can see nonlocal correlations restored by the use of a
nonlocal resource correlating the losses. Twin optical beams created in an
entangled Einstein-Podolsky-Rosen (EPR) state by an optical parametric
oscillator above threshold were subjected to 50% loss from beamsplitters in
their paths. The resulting severe degradation of the signature quantum
correlations observed between the two beams was then suppressed when another,
independent EPR state impinged upon the other input ports of the beamsplitters,
effectively entangling the losses inflicted to the initial EPR state. The
additional EPR beam pair was classically coherent with the primary one but had
no quantum correlations with it. This result may find applications as a quantum
tap for entanglement.

5
The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph