2023 Exam - Problem 1c

2023 Exam - Problem 1c

par Yago Pérez Pérez,
Nombre de réponses : 2

Hey

I computed the probability in a similar manner as to what is seen in the solution, except I ignored the "Charlie bit" since we just apply the identity to it, however I end up with a probability of 1, instead of 1/2. What exactly is wrong with my method? Do we really need to worry about Charlie's part too?


En réponse à Yago Pérez Pérez

Re: 2023 Exam - Problem 1c

par Nicolas Macris,
Yes you need to worry about charlie’s part too. There will be no cross term in the expansion of the square norm equ (12) because the states 0 and 1 of charlie are orthogonal! Then you find (13) with no double product cross term! Which eventually leads to 1/2 in (14).
In your handwritten calculation i dont ser the bits of Charlie, hence this calculation is probably wrong.