Hi all! Sorry for the bad english!
Please, can someone help me understand the setup from "entanglement between photons that never coexisted "?
So, we start with a bean from a laser, that hits a bbo crystal, makes two entangled photons (1 and 2), 1 gets measured (lets say its vertically polarised) and dies.
Photon 2 goes to (Where?), 2 more entangled photons are created there (how?) (Photons 3 and 4). Photon 2 gets entangled with they (how?), photon 4 gets detected and it shows its entangled with photon 1 (like it is measured as horizontally polarised ).
I Just want to know how it happens, please. Like "photon 2 hits another bbo cristal that generates the new two entangled pairs" or something like that! =)
Thanks Again! =)