The Heisenberg Limit · Phase Estimation Beyond Shot Noise
unseel.com · N probes · Δφ ∝ 1/N vs 1/√N · quantum Fisher information
FQ
Δφ
phase
Separable probes · SQL (1/√N)
Entangled GHZ/NOON state
Bloch sphere · collective spin
Heisenberg scaling (1/N)
Decoherence · loss reverts scaling
Unseel.com · The Heisenberg Limit: Phase Estimation Beyond Shot Noise