Hello,
I have some problems to understand how we are supposed to compute the global state of let's say 3 q-bits given that one of them was already measured and observed in one state.
So for example if I have the state
And it is given that C measures his q-bit in the basis { |0>, |1> } and the result of the measurement is |0>
What are the computations we are doing to find the resulting state ? I would compute the following : |0><0|
But I'm not sure if we are allowed to do it like this. And the result would be with the 1/sqrt(2) factor in the front. Is it right ?
I'm asking the question with the 1/sqrt(2) factor in the front because in the 2023 exam the result of this question is :
And the result after Charlie's measurement is : without the 1/sqrt(2) in the front. Why is this the case ?
If I'm wrong in the computation can you please explain how we are supposed to do it the right way ?
Thank you in advance for the help !