I have been reading about the exclusion principle a little bit, but I have some questions about it.
How does the information about the state of electrons get "passed around" so that other electrons in similar state can not have that same state? Is there some kind've information carrier?
Is there some unique force created by a set of quantum numbers for a fermion so that, the force then prevents another fermion with the same set of quantum numbers from being permitted? How do electrons know the states of other electrons to determine if their state is allowed?
Best Answer
Sometimes people say that the Pauli exclusion principle says that "two electrons can't be in the same state." This is not correct. It's not as though each particle has its own "state" that it keeps to itself. It's actually much deeper: the electron field itself has one state it's in (that's the whole point of quantum field theory) and crucially there are simply no states of the electron field corresponding to two electrons with the same spin, position, etc. There is nothing for it to "know," it's just what the quantum electron field is.
Fermionic fields are different from bosonic fields. A boson field also has a single state it's in, but the difference between a bosonic field and a fermionic field is simply that the boson field does have states that correspond to boson particles with the same position, spin, etc. Bosonic fields have way more states than fermionic fields.
(Actually, going a bit further, EVERY field together is really in a single universal state, but that's not really so important for the question at hand.)