- #36
PeterDonis
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fog37 said:So, when the total wavefunction is separable (i.e. it can be factored), it describes two systems that are two things:
a) Indistinguishable
b) Independent from each other
b), yes. a), no. There is no requirement that the two systems described by a total wave function that is separable be indistinguishable.
fog37 said:I guess it is possible to have, after the measurement on an entangled system formed by one-two electrons system, two subsystems (the electrons) that are independent and now also distinguishable
They're distinguishable because we measured them, which really means that the "distinguishable" systems are not just the electrons by themselves, but the electrons plus the measuring devices that recorded the results.
Also, as I said before, you can always take the electrons you just measured and have them interact again (which could be as simple as just bringing them back into the same small region of space), which will make them indistinguishable again, so now you have to treat them as a two-particle system with a wave function that has to be antisymmetric under exchange. In other words, the "distinguishability" only lasts as long as you don't change the state of the electrons from the one you measured.