Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Experimental measurement of nonlinear entanglement witness by
  hyper-entangling two-qubit states   We demonstrate that non-linear entanglement witnesses can be made
particularly useful for entanglement detection in hyper-entangled or multilevel
states. We test this idea experimentally on the platform of linear optics using
a hyper-entangled state of two photons. Instead of several simultaneous copies
of two-photon entangled states, one can directly measure the witness on single
copy of a hyper-entangled state. Our results indicate that hyper-entanglement
can be used for quick entanglement detection and it provides a practical
testbed for experiments with non-linear entanglement witnesses.

12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org