Quantum Teleportation — Bell Measurement & Fidelity

State & Noise

Input |ψ⟩ — θ (polar): 90° Input |ψ⟩ — φ (azimuthal): 0° Depolarizing noise p: 0.00 Phase flip rate q: 0.00

|Φ⁺⟩ = (|00⟩+|11⟩)/√2
Bell meas. → 4 outcomes
Bob applies: I, X, Z, XZ
Fidelity F = ⟨ψ|ρ_out|ψ⟩
Depol: ρ → (1-p)ρ + p·I/2
F_max = (3+4F_ent)/4 (Werner)

Fidelity F: —

Last Bell outcome: —

Correction applied: —

Alice shares a Bell pair |Φ⁺⟩ with Bob. She performs a Bell measurement on her qubit + the state to teleport, then sends 2 classical bits to Bob. Bob applies the appropriate Pauli correction. Noise reduces fidelity below 1. Classical limit: F_classical = 2/3.