- #1
StevieTNZ
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If we take two pairs of entangled photons (A+B and C+D), and take one from each pair (B and C) and perform a bell-state measurement on them (or another scheme that entangles photons A and D together):
(a) if the two other photons have not had their wave function collapsed, four-photon entanglement is created: http://arxiv.org/abs/quant-ph/0104047
(b) if the two photons had been measured, and then a bell state measurement occurred (or similiar), a different result is evident (i.e. not the same result as (a)).
I've seen (b) realized in delayed-choice entanglement swapping, but is there another scheme that would generate different results if measurement had occurred before photons A and D became entangled?
(a) if the two other photons have not had their wave function collapsed, four-photon entanglement is created: http://arxiv.org/abs/quant-ph/0104047
(b) if the two photons had been measured, and then a bell state measurement occurred (or similiar), a different result is evident (i.e. not the same result as (a)).
I've seen (b) realized in delayed-choice entanglement swapping, but is there another scheme that would generate different results if measurement had occurred before photons A and D became entangled?