I saw on the site Brilliant.org a question witch is:
"Let's say I'm given a quantum wire, I measure it and find it charged "on". If I come back some time later, what state should I measure?"
And the answer was: Charged "on".
And they explain: "If a quantum wire is measured to be "charged", then for any following measurements of the same isolated quantum wire, we would expect to measure the same charge and observe the same state."
- My question is: doesn't the system evolves between the measurement at t=0 and t>0, then the system would return in a combination states, so we don't expect the same state?? (we can do the same experiment with a qubit)