> Is it correct to say that two separate entangled particles are now one-and-the-same? It's not. If they were literally the same then swapping them should have

> Is it correct to say that two separate entangled particles are now one-and-the-same? It's not. If they were literally the same then swapping them should have no effect, and you shouldn't be able to distinguish whether you applied effects to one qubit or the other. But often this is not the case. For example, the state |00> + |01> - |10> + |11> is a maximally entangled state but applying the swap operation to it produces a different state. And if I give that state to you, and you secretly apply a bit flip to one of the qubits before giving it back to me, I can do measurements that determine which one you flipped over. There are some entangled states where the swap operation has no effect, but there are no states where all possible operations on both qubits become identical. They're never literally the same.