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reilly said:My apologies, I misread your superimposed state vector.
But for the life of me, I don't understand how you get such a state. If you could explain via the standard QED interaction and Schrodinger Eq. solutions -- even using non-relativistic perturbative solutions -- I would be most grateful.
Thanks,
Reilly Atkinson
http://arxiv.org/abs/0805.2853" mentions some ways to achieve the desired result in a practical way. Take e.g. the entangled state described by Eq. 27 on page 13:
1/sqrt(2) [|a>|a'> + |b>|b'>]
Here |a> and |b> are spatial modes for a photon and the primed states are different spatial modes for another photon. Then you don't have single photon interference, but you do have interference when you measure two photon correlations. All this is quite obvious.
But if you try to interpret the result classically, you get exactly what I wanted to show: You don't get interference even though the light from the spatial modes a' and b' should interfere classically. In case of the state:
1/sqrt(2) [|a'> + |b'>]
Then there would be inteference. In the classical picture, you cannot see the difference between the two cases. So, it is possible to create classical waves that fail to behave as predicted by classical theory.
This is true, in principle, for all classical wave phenomena. You could theoretically create two sources of sound waves such that they should interfere, yet you can make them fail to interfere if the phonons are in certain entangled states (whith other phonons or with some other degrees of freedom)
So, the conclusion must be that you don't necessarily get classical behavior in the classical limit. Or, perhaps one should say that classical wave phenomena like electromagnetic waves are in fact macroscopic quantum phenomena...
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