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Speaker:
Robert E. French
Polarization Entanglement

Date: 2010-05-08 Time: 07:00 - 09:00 US/Pacific (8 years 10 months ago)
America/Los Angeles: 2010-05-08 07:00 (DST)
America/New York: 2010-05-08 10:00 (DST)
America/Sao Paulo: 2010-05-08 11:00
Europe/London: 2010-05-08 14:00
Asia/Colombo: 2010-05-08 19:30
Australia/Sydney: 2010-05-09 01:00 (DST)

Where: Online Video Conference
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Description

In this presentation I discuss the feasibility of testing a physically realist account of polarization entanglement in terms of properties of electromagnetic fields together with advanced waves linking the detectors of the experiment with a down conversion crystal. Previous accounts of advanced waves, such as those of David Klyshko and of John Cramer have held either that the advanced waves go backwards in time or take their existence just instrumentally and not realistically. I find claims to backwards causation, if taken realistically, to be extremely implausible though. My alternative account of advanced waves keeps everything in the present, albeit with a special reference frame and an emission theory of light, whereby a joint absorption event occurs during the absorption time at the two detectors and can be measured by a coincidence counter.

In my account of polarization entanglement, the initial probability for joint absorption of down-converted light is given by a product of the intensities of the electromagnetic energy fields with a joint probability amplitude function which I account for in terms of a mixture of rotational waves associated with the electromagnetic force fields which are present at the detectors. This results in a cross term which cannot be factorized. I then hold that the mixture of polarized energy fields present at each detector is jointly absorbed so that the non-mixed polarized energy fields (which are measured in terms of the angle between the two polarizers behind the respective detectors) are drawn from the sets of mixed energy fields jointly present at both detectors by means of the advanced waves. I show how it is possible to account for each of the four Bell states by different variants of the experimental setup.

I believe that this account is testable by means of blocking the advanced waves, either by a mechanical chopper or possibly by a pockels cell driven by a fast driver. The idea here would be to block the optical pathway at a location just subsequent to the down- conversion crystal at the time of the joint absorption. For a 100 kHz chopping or driving rate this would require 3 km of optical fiber in both directions. If the advanced waves linking the two detectors are blocked, the correlations associated with polarization entanglement should then disappear. It is now routine to put down-converted light into even longer fibers and both mechanical choppers and pockels cell drivers are commercially available at 100 kHz. Thus the experiment should be feasible with today� technology, and I discuss the relative merits of the different blocking techniques.