Question

Suppose we are given a single qubit which is either in the state |u> = cos(pi/8) |0> + sin(pi/8) |1> or |v> = cos(3pi/8) |0> + sin(3pi/8) |1>. We measure this qubit in the standard basis and guess u if the outcome is 0 and guess v if the outcome is 1.

(a) What is the probability that you guess right?

(b) Is there a measurement which is correct more often?
Yes
No

Answer 1

b- no

Answer 2

a) 0.853

Answer 3

a) What quantum state do you have to input in order to get output |00⟩ ?

b) What quantum state do you have to input in order to get output |11⟩ ?

Answer 4

(c) What quantum state do you have to input in order to get output 1/2ã(|00⟩+|11⟩)?

Answer 5

Helppp

Answer 6

u are all cheaters on the exam and will be reported.

Answer 7

lolol at Anonymous

Answer 8

:D im glad someone has a sense of humour..

Answer 9

If the first qubit is in the state 2/sqrt(5)|0> - 1/sqrt(5)|1> and the second qubit is in the state 1/sqrt(2)|0> - i/sqrt(2)|1>, what is the state of the composite system?