My understanding of the linked PDF is that :
the usual interference pattern is NOT observed for the right particles if the left stream of particles are just left alone;
but if the left stream of particles (which-path information) are quantum erased, the the usual interference pattern can be...
In the delayed choice experiment the original photon is down-converted after it has passed the silt.
In my scenario, the original photon is down-converted way way before the right particle passes the slit. Does that make a difference?
I create 1000 pairs of entangled particles and let them travel very far away.
Then I let the 1000 right particles pass through a double slit experiment.
At the time when the right particle has passed the slit, but not yet hit the screen, I can choose to detect the 1000 left particles. If I...
What if:
1)
we put a swtich gate on the bottom slit. The bottom slit is normally closed, but we time it so we open it just before a photon/electron MAY arrive.
so far this will yeild the same result as traditional experiment?
2)
usually the two slits are close by, but we move it very...