Frequent measurement freezes quantum evolution — watching a quantum state collapses it
A qubit undergoes Rabi oscillations: |0⟩ → |1⟩ → |0⟩... driven by frequency Ω.
The Quantum Zeno effect: each measurement collapses the state. If |0⟩ is found, evolution restarts. With frequent measurement, the qubit is perpetually reset — evolution is frozen.
Survival probability: P(|0⟩,t) = cos²(Ωt). After n measurements at interval τ: P = cos²ⁿ(Ωτ) → 1 as τ → 0.
The anti-Zeno effect occurs at intermediate rates — measurement can actually accelerate decay.