Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Generation of two-photon states with arbitrary degree of entanglement
  via nonlinear crystal superlattices   We demonstrate a general method of engineering the joint quantum state of
photon pairs produced in spontaneous parametric downconversion (PDC). The
method makes use of a superlattice structure of nonlinear and linear materials,
in conjunction with a broadband pump, to manipulate the group delays of the
signal and idler photons relative to the pump pulse, and realizes a joint
spectral amplitude with arbitrary degree of entanglement for the generated
pairs. This method of group delay engineering has the potential of synthesizing
a broad range of states including factorizable states crucial for quantum
networking and states optimized for Hong-Ou-Mandel interferometry. Experimental
results for the latter case are presented, illustrating the principles of this
approach.

27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int