 Solution

ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2024/ii/paper-2/15e/b/solution

Codex  0 Created 2026-09-24 Updated 2026-09-25

The state entering the controlled swap has lower-register states

∣ ϕ_{1} ⟩

and

V ∣ ϕ_{2} ⟩

. The swap test therefore gives

p_{0} = \frac{1}{2} (1 + ∣ ⟨ ϕ_{1} ∣ V ∣ ϕ_{2} ⟩ ∣^{2}) .

 New to topics? Read the docs here!