Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: One-step direct measurement of the entangled W states with cross-Kerr
  nonlinearity   We propose a scheme to directly measure the entangled W states with
cross-Kerr nonlinearity mediums. This scheme can measure three-photon,
four-photon, and even N-photon W states in one step. Only PBSs and cross-Kerr
nonlinearity mediums are used in this scheme, which is feasible for
experiments. We describe the three-photon W states measurement process and
extend it to four-photon and N-photon W states.

15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int