Polarization Eraser & Entanglement

[DrChinese]

Following Fig. 1 in the following paper:

Eberly (2002): Bell inequalities and quantum mechanics

In an ideal case (this is far from easy to do): Send an incident beam from one side of entangled photon pairs into a beamsplitter, and then recombine the outputs back into a single stream. Let's call the outputs of the beamsplitter as X and Y, where X and Y are orthogonal. The theory is that the recombined stream X+Y will still evidence entanglement, as the polarization has been erased.

In the next step, let's do the same thing for both Alice and Bob. You end up with 4 outputs from the 2 beamsplitters, which are before erasure:

Alice X
Alice Y
Bob X
Bob Y

1. So if you take the recombined streams (Alice X + Alice Y) and (Bob X + Bob Y), they are still entangled. As far as I know, this experiment (as described by Eberly in more complex versions) has not been performed. Does anyone know of a reference on this?

2. Here is a strange one: Alice X and Bob X are identical streams, as are Alice Y and Bob Y. I believe that theory would say that (Alice X + Bob Y) and (Bob X + Alice Y), if they could be combined, would be entangled! Were that true, it would indicate that the probability waves are "real" even though the observable properties apparently are not. Any thoughts? Has anyone seen anything on this?

 

[zonde]

Probably no one has bothered with experiment described by Eberly because his derivation is erroneous as explained by Ryff here http://arxiv.org/pdf/0902.1724"

 

[Entropia]

I find this paper by Eberly (2002) on Bell inequalities and quantum mechanics to be quite fascinating. The concept of using a polarization eraser to demonstrate entanglement is a novel and intriguing idea. However, as the author notes, this experiment has not been performed in its more complex versions.

Regarding the strange scenario where Alice X and Bob X are identical streams, as are Alice Y and Bob Y, I agree with the author's belief that theory would suggest that (Alice X + Bob Y) and (Bob X + Alice Y) would be entangled if they could be combined. This would indicate the importance of probability waves and their role in quantum mechanics.

I have not come across any references on this specific scenario, but it would be interesting to see if any experiments have been conducted to test this theory. It could potentially provide further insight into the nature of quantum mechanics and the role of probability waves in entanglement.

Overall, this paper presents some intriguing concepts and raises interesting questions for further research. I look forward to seeing future experiments and studies on the polarization eraser and entanglement.