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I was looking through Zeilinger's "Dance of the Photons" where I re-read the section of three-photon entanglement. If one photon is measured in H polarisation, the other two take on H - likewise with V polarisation.

What I find interesting is if we measure one photon and its H polarisation, another (delayed) at 45 degrees, and the last at vertical - when the first photon takes on H polarisation, don't the other two? So when the last photon meets the V polarised filter, shouldn't it fail? But according to GHZ results, it should be vertical.

So the other two photons are NOT in H polarisation when the first one meets the polariser? Or the first photon is NOT in H polarisation - evolves as a superposition in accord with Scrodinger equation (no collapse occurs).

Unless I've mis-understood something?

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# GHZ entanglement

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