Towards loophole-free Bell inequality test with preselected unsymmetrical singlet states of light
Magdalena Stobińska, Falk Töppel, Pavel Sekatski +1 more
Can a Bell test with no detection loophole be demonstrated for multiphoton entangled states of light within the current technology? We examine the possibility of a postselection-free Clauser-Horne-Shimony-Holt (CHSH)-Bell inequality test with an unsymmetrical polarization singlet. To that end we employ a preselection procedure which is performed prior to the test. It allows using imperfect (coarse-grained) binary photodetection in the test. We show an example of a preselection scheme which improves violation of the CHSH inequality with the micro-macro polarization singlet produced by the optimal quantum cloning. The preselection is realized by a quantum filter which is believed not to be useful for this purpose.
arXiv:1304.7460•Physical Review A•Feb 21, 2014•9 citations