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Multiple choice
In this checkpoint, QPE is run on the S gate with eigenstate
∣
1
⟩
|1\rangle
∣1
⟩
(eigenphase
ϕ
=
1
/
4
\phi = 1/4
ϕ
=
1/4
) using a 2-qubit counting register. What bitstring does the counting register yield with certainty?
🔬 try it before you answer
11 (because
ϕ
=
1
/
4
=
0.11
\phi = 1/4 = 0.11
ϕ
=
1/4
=
0.11
in binary)
01 (because
ϕ
=
1
/
4
=
0.01
\phi = 1/4 = 0.01
ϕ
=
1/4
=
0.01
in binary)
10 (because
ϕ
=
1
/
4
=
0.10
\phi = 1/4 = 0.10
ϕ
=
1/4
=
0.10
in binary)
00 (because
ϕ
=
1
/
4
\phi = 1/4
ϕ
=
1/4
rounds to zero)
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