Bell-type Polarization Exp: Uncorrelated Photon Pairs & End of Nonlocality?

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In summary, the authors of this experiment discuss how the measurement procedure in Bell-type experiments can yield a polarization relation between two photons, whether they are entangled or not. They also suggest that the CH inequality can only be conclusively tested when the analyzing instrument and final state-preparation instrument do not coincide. However, this experiment's findings seem to contradict the predictions of quantum mechanics and have been met with skepticism. The authors also do not take into account the Poissonian or Bose-Einstein-like photon number distribution in their analysis, which could affect the results.
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A very interesting Bell-type experiment using uncorrelated photons
A very interesting experiment:
Bell-type Polarization Experiment With Pairs Of Uncorrelated Optical Photons
M. Iannuzzi, et al.
in arXiv:2002.02723 [quant-ph] or Physics Letters A 384 (2020) 126200
The autor(s) conclude:
"We may therefore understand that the measurement precedure adopted in the Bell-type experiments yields the polarization relation between the two members of a pair, either entangled or not entangled, in their finalpreparation state.
In particular, for either quantum or classical physical systems, sinusoidal correlations relation of p12(a, b) substituited into the CH inequality, may cause its violation. Consequently we believe that the CH inequality will be conclusively tested only by relating it to Bell-type experiments with an analysing instrument and a final state-preparation instrument that do not coincide."
This seems to be very strange. This is the end of the "nonlocality" paradigm?
 
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As far as I can see, this experiment claims violation of Bell-type inequalities without entanglement. This is in contradiction with the predictions of quantum mechanics. I am very skeptical.
 
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If i understand their work correctly, they are claming a variation of Bertlmann's socks. Wasn't this disproved mathematically by John Bell in 1981?
 
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The number of issues with this manuscript is very long. Just to start with, the photon bunching they see is not expected for two independent lasers, unless they are filtered strongly. In that case they become quasithermal light sources.
Along the same lines, they use two lasers instead of entangled photon pairs, but do not consider the Poissonian (or Bose-Einstein-like for quasithermal light) photon number distribution lasers show. So there are no photon pairs arriving, but strongly varying numbers of photons. This of course needs to be taken into account in a correct analysis and if I remember correctly, the derivation of the CH-inequality assumes exact photon pair states and not sometimes 2 photons, sometimes just 1 and sometimes 7.
 
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FAQ: Bell-type Polarization Exp: Uncorrelated Photon Pairs & End of Nonlocality?

What are Bell-type experiments?

Bell-type experiments are designed to test the predictions of quantum mechanics against classical intuitions about the nature of reality, particularly concerning the phenomenon of entanglement. They typically involve measuring correlated properties of pairs of entangled particles, such as polarization, to determine whether the results align with quantum mechanics or classical local hidden variable theories.

What is meant by "uncorrelated photon pairs" in this context?

Uncorrelated photon pairs refer to pairs of photons that do not exhibit any quantum entanglement or correlation in their properties. In Bell-type experiments, using uncorrelated photon pairs serves as a control or baseline to demonstrate the difference between classical predictions and the behavior of truly entangled photons, which show strong correlations in their measured properties.

How do Bell-type experiments demonstrate nonlocality?

Bell-type experiments demonstrate nonlocality by showing that measurements on entangled particles can influence each other instantaneously, regardless of the distance separating them. This phenomenon contradicts classical notions of locality, where information cannot travel faster than the speed of light. The violation of Bell's inequalities in these experiments supports the nonlocal interpretation of quantum mechanics.

What is the significance of the "end of nonlocality" in quantum mechanics?

The "end of nonlocality" refers to the idea that once quantum mechanics is fully understood and all its implications are accepted, the classical notion of local realism may no longer hold. This shift in perspective challenges our understanding of causality and the fundamental structure of reality, suggesting that entangled particles can exhibit correlations that cannot be explained by any local hidden variable theory.

What are the implications of Bell-type experiments for our understanding of reality?

The implications of Bell-type experiments for our understanding of reality are profound. They suggest that the universe may be fundamentally interconnected in ways that defy classical intuitions. Quantum entanglement implies that particles can be correlated in ways that cannot be explained by classical physics, leading to philosophical discussions about the nature of reality, observation, and the limits of human knowledge in the quantum realm.

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