DrChinese said:
But you completely missed what is being pointed out by the quote, and it in no way matches your ideas. They simply point out that if you don't discriminate between the 2 Bell states |Φ−〉23 and |Φ+〉23, there is no underlying Entangled state statistics
Yes, the fact that not discriminating Bell states removes the correlations is precisely my point. You can clearly have separable measurements of HHVV which have Bell statistics embedded in them that are not distinguished by those measurements. Cleaarly there is something lost in translation here because to me this paragraph looks like it is repeating what I said.
DrChinese said:
2. It's a shame that the Nobel committee overlooked this [/sarcasm]brilliant and well-accepted[/end sarcasm] work by Fankhauser when vetting Zeilinger for the Physics Nobel. If they had read it, they certainly would have crossed off Zeilinger's name for the prize.
I don't see any argument here and the paper clearly is not refuting anything about non-locality.
DrChinese said:
But there is NO MIXING of the |Φ−〉23 and |Φ+〉23 subensembles as you state/imply
Yes, there is no mixing of the separable and non-separable measurements. Just like in the delayed eraser experiment there are clearly different screens where the interference photons and which-way photons go. But if you mix the interference photo data it just adds together into the which-way data. Similarly here, the authors explicitly mixed the non-separable data and produced what is statistically indistinguishable from the separable data. The point is that the fact that there are some measurements with correlations in other bases and some measurements with correlations in only one base is not a miraculous point. Because the experiment clearly shows that you can go from one to the other by mixing the data, or using measurements that fail to make discriminations that a Bell state measurement would. We have two entangled systems which in virtue of their entanglement are always going to produce a predictable set of results if you measure them a bunch. Even if you measure an entangled system on different bases, you know what measurements you would have got had you measured them on the same basis. The Bell state and separable measurements are two ways in which we can establish coincidences between the two different entangled systems but one enables a different kind of coupling due to the coherence and phase that is not accessible in the separable case.
.
DrChinese said:
4. There is no such thing as "transitivity" of entanglement, and I requested a suitable reference on this completely wrong idea.
When the 2 and 3 photons are correlated (both H or both V), this does not lead to any seemingly entangled correlation whatsoever between photons 1 and 4 EXCEPT when Alice and Bob measure them on the H/V basis. Either 1 and 4 become entangled due to the swap, or they don't. When they are entangled, the 1 & 4 photons will be strongly correlated on ALL bases. If they are separable, that doesn't happen. The statistics, as shown in Fig 3, are completely different. If you were correct, those graphs would look alike. Again, this should be obvious - it's the main result of the paper! I know you can't think they are committing scientific fraud
The answer to this is that in the two parts of figure 3 we have two examples of transitivity: transitivity of separable correlations and the transitivity of entanglement correlations. If you have correlations for one basis for 2 and 3, then transitivity means only allowing correlations between 1 and 4 in one basis. If you have correlations for more than one basis for 2 and 3, then transitivity means you will have correlations between 1 and 4 in more than one basis.
I'm pretty sure this paper here evokes the same kind of idea of transitivity:
https://scholar.google.co.uk/scholar?cluster=10636160464314492908&hl=en&as_sdt=0,5&as_vis=1
e.g.
"Alice’s measurement ‘‘steers’’ the state of particle 2, which is sent to Vicky, in turn influencing the state of particle 3 (and hence also particle 4) through Vicky’s Bell-state measurement. This does involve spatial nonlocality (which was not at issue), but no temporal nonlocality. Finally, Bob performs a measurement on particle 4. Like was the case for the Ma et al.-experiment, the outcomes of the first and final measurement will in general not display Bell correlations. [But] If we post-select the subsample where the outcome of Vicky’s Bell-state measurement was ‘‘Bellstate
+’’, however, we do observe Bell correlations:"
"It is important to note that, similarly to the non-delayed case, the
correlations observed in the Ma et al. and Megidish et al. experiments only obtain if we sort the outcomes obtained by Alice and Bob in different subsamples corresponding to the possible outcomes of Vicky’s measurement, and consider the outcomes within each subsample. If we ignore the outcomes of Vicky’s measurement and consider all the outcomes obtained by Alice and Bob together, we will find no correlation. This suggests a different possible explanation of the Bell-type correlations; namely that they are a statistical artefact arising due to this post-selection, rather than any mark of genuine entanglement between particle 1 and particle 4."
DrChinese said:
As you say, "a decision to physically interact" does in fact change which bucket the data point is added to
And this distinction between separability and non-separability exists in the Barandes formulation.
I think something like the following is probably what would happen in the Barandes formulation. But before starting it has to be noted that what Barandes has done so far does not have the different bases or precisely modeled spin so this is a story of how the kinds of elements present in the Barandes theory would deal with entanglement swapping. But at the same time, the central idea of Barandes' theory is that any quantum system can be translated into an indivisible stochastic one so if he has not made an error, the indivisible stochastic model of entanglement swapping should be possible just in virtue of the fact we are talking about quantum systems.
Right, so you have two indivisible stochastic systems 1 & 2 and you let them locally interact, causing a correlation that leads to a non-separable composite system. The two parts of the composite system travel far apart but the correlation is maintained due to the memory of the composite indivisible transition matrix. We can say the same for indivisible stochastic systems 3 & 4.
We do a separable measurement which establishes a one-to-one correspondence for results of 2 & 3 in one basis effectively by picking out pairs of results. No coincidences in other bases are found for 2 & 3 because this requires a non-separable relationship between 2 & 3 which we do
not have due to it being a separable measurement. The coincidences in 2 & 3 mean we can follow the following logic: result in 1 implied a result in 2. Result in 2 implies a result in 3, result in 3 implies result in 4. Because 2 & 3 would never show coincidences in other bases, this chain would be broken if we tried to follow it in the other basis.
Or we could do a non-separable measurement on 2 & 3 which not only establishes a one-to-one correspondence in one basis but implies this would be the case in all bases because it picks out a correlation or would-be-coincidences in all bases, the same kind of correlation that was implied by the local interactions that produce entanglement for 1 & 2 or 3 & 4 in the beginning. We can then follow the chain of reasoning suggested before but in all bases. Even if we measure 1(4) and 2(3) in different bases, the correlation between 1 & 4 is implied by the fact that if we had measured 2 in the same basis, we know what the answer would have been. We then know what the answer would have been in 3 which implies the result in 4 if you measure it in the relevant basis. We can then additionally look at the swap in the sense that a non-separable state has been created for 2 & 3. The Bell state measurement also then acts as a division event for systems 1 & 2 and 3 & 4, breaking their respective entanglements. However, we can still note the non-separable correlation present in 1 & 4 (due to the chain of reasoning before) which is just identical to an entanglement. Non-separable systems (entanglements) have been swapped between the 4 particles.
If we do not perform the measurements, no correlations between 1 & 4 occur because there is no one-to-one correspondence. 1 & 4 go through all their possible outcomes they were going to go through as an independent entangled system, 3 & 4 go through all their possible outcomes they were going to go through as an independent entangled system. No one-to-one correspondences of results have been established between 2 & 3 so if you examine all the possible outcomes of 2 and all the possible outcomes of 3 side-by-side, it just looks random because you are not isolating any specific sets of one-to-one correspondences.
Ofcourse, there is no physical collapse in Barandes' system. When the experimenter couples his measurement device to a system in general he cannot choose the measurements he finds. To isolate the individual outcomes of measurements in this formulation as you would need to for a Bell state (or separable) measurement, the only thing you can do is statistical conditioning (which is what Barandes identifies as the formal source of collapse). And when you condition on results of 2 & 3, only then can you follow the chains of correlations or coincidences above allowed respectively by non-separable and separable measurements.
In addition because there is no physical collapse and only statistical conditioning, delays do not matter. The correlations are established at source and just remembered until measurement as systems 1 & 2 or 3 & 4 evolves. It doesn't matter who measured what first because the remembered correlation dictates what is going to happen at measurement. The separable and non-separable measurements then just pick out one-to-one correspondences between 2 & 3.
