Department of Mathematics, University of Zagreb,
GF, Kaciceva 26, POB-217, HR-10001 Zagreb, Croatia; mpavicic@faust.irb.hr; http://m3k.grad.hr/pavicic
Abstract.
Two previously discovered effects in the intensity interference: a
spin--correlation between formerly unpolarized photons and a spin
entanglement at-a-distance between photons that nowhere
interacted, have been used for a proposal of a new preselection
experiment . The experiment puts together two photons from
two independent singlets and makes them interfere at an
asymmetrical beam splitter. A coincidental detection of two
photons emerging from different sides of the beam splitter
preselect their pair-companion photons (which nowhere
cross each other's path) into a nonmaximal singlet state.
The quantum mechanical nonlocality thus proves to be essentially
a property of selection. This enables a loophole-free experimental
disproof of local hidden-variable theories requiring detection
efficiency as low as 67% and an exclusion of all nonlocal
hidden-variable theories that rely on some kind of a physical
entanglement by means of a common medium.
PACS numbers: 03.65.Bz, 42.50.Wm
Keywords: four photon interferometry, asymmetrical
beam splitters, non-maximal singlets, quantum optics,
quantum nonlocality, quantum teleportation,
loophole-free Bell experiment.
Mladen Pavicic
Max-Planck-AG Nichtklassische Strahlung,
Humboldt University of Berlin, D-12484 Berlin, Germany.