Dear community,
by repeating some quantum mechanics and also reading some "ancient" papers about it, once again I stumbled upon the feature of quantum entanglement. So the matter at issue here is: Does entanglement really only have to do with the knowledge of the system (no nonlocality, only what we know changes), or is it a "real" effect on the objects under consideration. To this regard, I have the following question:
Assume having two electrons that were prepared in a way that they have a common wave function with known initial conditions, i.e. are entangled in a controlled way. Now suppose two double slit experiments, one for the first, the other one for the second electron. For simplicity, the electrons have opposite momenta p and p, so the two apparatuses are somewhat "in line". Now, shouldn't it be possible (in principle) to
i) do no measurement, so one sees an interference pattern at both double slits when repeating the experiment often enough, ii) do a measurement on apparatus 1, leading to the disappearance of the interference pattern in this system and then comparing it to the pattern of the other apparatus?
So, if the interference pattern at the other (unmeasured) apparatus also vanishes, the entanglement is indeed "real", if not, it is really just about mathematical formalism in q.m.?
What do you think about that? And: Do you know if such experiments already exist? The experiments with polarization somehow did not convince me, however maybe also because I do not fully understand what is tested there.
Thanks
