How do I start new thread?by ljagerman Tags: None 

#1
Feb2312, 09:55 PM

P: 1

My first use of Physics Forums.
I have a question not addressed so far, as far as I can tell. It's in the area of quantum math for entangled state. But I cannot figure out how to ask it! Is there a "new thread" or "new question" tab anyplace? Is there a menu item for new threads or new questions? If so, where. In case this is the place, here is my question. Interested in recent tests of quantum nonlocality in 3photon GHZ entanglement. Looking at key paper by Pan, Bouwmeester, Daniell, Weinfurter & Zeilinger in Nature, 403, 2 Feb 2000, p. 515518. Key equation is for entangled 3photon GHZ state; their equation (1): Ψ⟩=1/√2 〖(H⟩〗_1 H⟩_2 H⟩_3+V⟩_1 V⟩_2 V⟩_3); no problem here. Then the experiments introduce optical devices to rotate polarization and induce circlual polarization; equations here are (their (2) and (3): Pair (2): H/⟩ =1/√2 H⟩+V⟩) and V/⟩ =1/√2 H⟩+V⟩) Pair (3): ʘR⟩ =1/√2 H⟩+iV⟩) and ʘL⟩ =1/√2 H⟩iV⟩) This looks like simple vector trig in a unit circle. Now they solve (1) above with (2) and (3), and they arrive at their equation (4): Ψ⟩=1/2 〖(ʘR⟩〗_1 ʘL⟩_2 H/⟩_3+ʘL⟩_1 ʘR⟩_2 H/⟩_3 +ʘR⟩_1 ʘR⟩_2 V/⟩_3+ʘL⟩_1 ʘL⟩_2 V/⟩_3). My question: How did they get to (4)? What vectoralgebraic (?) steps did they use? I know a little about Dirac notation, wave functions, etc, but not enough to see how equation (4) was derived. Please help if you can! Thanks! 



#2
Feb2312, 09:59 PM

Admin
P: 8,542

It's the same process in every forum. You found how to do it in the Feedback forum. Replicate that process in another.




#3
Feb2312, 10:15 PM

P: 1

Got it: So now it's in 2 places, but I guess not harm. Please see in Physics, Quantum mech. area



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