I have 2 questions i would really like to find an answer to: if we have a quantum pair, we can determine whether 2 quanta are entangled or not assuming that we have access to the information of both of them. so if we have a quantum "trio" instead of a quantum pair, does the information about 2 out of 3 quanta suffice to determine whether those two quanta are entangled? if not, why not. the only entanglement i am interested in is the one of the 2 quanta that are tested. the 3rd one is not important for question one. the second question is: if one out of those 3 entangled particles wave functions collapses, this should break the entanglement of all 3 particles and collapse their wave-functions, right?
this is a rephrased version of my original question, in hopes that there would be less confusion.
original question was:
It is my understanding that you can entangle multiple quanta, so that you don't get "quantum pairs" but for example "quantum-trios" etc. I base this assumption on the following study: https://www.nature.com/articles/ncomms13251 Further I believe to know that once the wave function of an entangled particle is collapsed, the entanglement is "broken". I know that there are several resctrictions for faster than light communication with a quantum pair/quantum pairs. I do base following thought experiment on the assumption that one does need only access to the information about 2 out of three quanta to determine whether an entanglement is existent or not.
If we assume a entanglement of atleast 3 quanta(trio) and person (A) has 1 quantum, person (B) has two quanta and person (A) collapses the wave-function, (B) should be able to determine that his 2 quanta are no longer entangled, and faster than light communication would be possible. I don't think it is that simple, but I lack the knowledge. What am I missing?