exam 2021. Problem 3, question c

Re: exam 2021. Problem 3, question c

by Guifré Sánchez i Serra -
Number of replies: 0
I think they should do nothing because the asked protocol requires that the state the Bob and Charlie have jointly after Alice's measurement can be either alpha 00 + beta 11 or alpha 00 - beta 11. Since in the case Alice measures B4 the state in B&C lab is just alpha 00 - beta 11, nothing has to be done.