Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Heralded Two-Photon Entanglement from Probabilistic Quantum Logic
  Operations on Multiple Parametric Down-Conversion Sources   An ideal controlled-NOT gate followed by projective measurements can be used
to identify specific Bell states of its two input qubits. When the input qubits
are each members of independent Bell states, these projective measurements can
be used to swap the post-selected entanglement onto the remaining two qubits.
Here we apply this strategy to produce heralded two-photon polarization
entanglement using Bell states that originate from independent parametric
down-conversion sources, and a particular probabilistic controlled-NOT gate
that is constructed from linear optical elements. The resulting implementation
is closely related to an earlier proposal by Sliwa and Banaszek
[quant-ph/0207117], and can be intuitively understood in terms of familiar
quantum information protocols. The possibility of producing a ``pseudo-demand''
source of two-photon entanglement by storing and releasing these heralded pairs
from independent cyclical quantum memory devices is also discussed.

26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th